The most important adjetive for this machine is, AMAZING! First, I'd like to recommend anyone researching this or any product... Read reviews. The good and the bad! Then, look for the trends in those reviews and from there, determine for YOU what is important versus what is not important. A handful of bad reviews that involve complaining about things that have nothing to do with the product specifically (i.e. packaging, delivery, etc) or a small percentage of reviews that have minor "breaks" or other minor problems versus the hundreds or better yet, thousands of great reviews on the same product, those "bad" reviews may need to be taken lightly. Unless, of course, those things are important to you. Do consider this. It doesn't matter how a product is made (assembly line or hand made), there will ALWAYS be faults. No matter the company or how good the product is overall. Obviously, the fewer problems the better but if you are seeing hundreds or thousands of good reviews to a few dozen or so negative, then that would be a reasonable percentage of errors with any good to great product. I know some people will have multiple bad experiences with the same product where others have no issues. There are a multitude of reasons that could happen but look for the overall, not just that one review. That said, I recommend and do this myself, but when looking for trends, if the bad reviews are all because something breaks but maybe its a different piece each time, then there may be an obvious trend. I would possibly take that into consideration. It may not make my decision for me, but the trend of what users say about the product is what I'm looking for and it's paid off for me quite well. Bottom line of what I'm trying to say is, don't just look at one or two reviews and don't just look at the good or the bad, but rather review as best as you are comfortable with on both ends of the spectrum and decide what trends you find and how those trends impact your decisions. For me, reading actual buyers/users reviews are better in almost all circumstances then any lab testing or any company that does product reviewing. With that, I have started my research with companyreviews, but in the end, WE'RE the end user! It is our perspective and experience that matters most. I'd rather gain real world end user perspective then read an article that may or may not be paid for to make a statement one way or the other.On to my review. I have to say this first. When I was researching and reading reviews, my first thought, when I decided I was gonna make this purchase, was "I hope my money doesn't go to waste, but if I get even one great cleaning, that is better than I could pay any over priced "professional" with a oversized "vaccum" in their van, that doesn't even lift out the dirt but just wets the floor and kinda cleans. Then IT'S WORTH IT." I mean not to offended any professional out there but simple soaping the floor and suctioning it up isn't cleaning. That's multiple experiences and eventually, history doesn't lie.Now, I did follow the recommendation of at least one reviewer in this review group that doubled up on the solution, and it worked. I'm not recommending that for you. Just telling you my experience and what worked for me.Now I know you saw the pictures and probably felt ill just looking at that floor. Obviously, we thought so too. It's disgusting and thus we purchased the Big Green Machine. We can compare this unit to the many other ways we've tried to keep carpet clean in companies paid and products purchased and nothing else has come close to this.We have SEVERAL pets to which I won't mention how many but I will say I don't have enough fingers to count them all. We love our fur babies and other pets. We also like having a clean floor and clean house. The floor is the biggest battle in our household.Nothing is more off putting then walking into someone's house and it wreaks of animal urine. But when it's your own home and everytime you come home it smells. YUCK! Multiply that smell by 5 and and that is what anyone else coming into your home smells. We've been there. We were just there. We didn't want to host anything because of the floors. But now, I can very happily and more than confidently say that we've found our cure. This machine is just straight up, Amazing. I've never had a "professional" even come close to cleaning carpets as well as this BIG Green does. If I could find a professional to do this it would almost absolutely cost more than this machine, but I can get multiple uses out of this, as long as well cared for. You can see it for yourself in my posted pics. That dirty floor there is several months of pet stains because the moment we moved into this house my first dog discovered the location of the previous tenant's dog's "place" within less than 5 minutes being in this home. We even waited outside with our dogs before going in to this house for the first time, while they all "did their business" and still she started this disgusting trend. So let's chalk it up to this. More than a handful of household free roaming pets and 11, that's right, ELEVEN months of this.So here's what we did. Machine arrived as quoted at time of purchase. That very next available day off, Saturday, I carefully went through the included manual and honestly, this machine looks like it could or should be difficult, but it truly isn't. Very easy to unpack, assemble, dis-assemble, and re-assemble again. That's important as you will have to empty this unit and refill with clean solution every one gallon. VERY easy to push/pull. Don't leave solution in tank or in machine. Keep all parts clean and dry when in storage. That's how I've best kept any product that uses liquids with electrical devices. Never store liquids in the machine or attachments when not in use. Unfortunately sometimes that means tossing any leftover portions unless you wish to find another way to store the liquid. Diluted solution is not recommended to be put back in with concentrate as number one, it likely won't fit, and number two, you'll ruin the concentration level of the original solvent. Next, I went to work on the floor. Now, I do have to say many people and these products suggest to pretreat. I did NOT pretreat. I wanted to see how this product (with double amount solution) would actually hold up. I started with a small space (4' x 4' landing) and immediately could see the difference. Then when I started the first trip down the hallway, my wife suggested to take before and after photos. That's what you find above. My process with doing this was to make a forward pass (I divided the hallway into 3 sections. Moving side to side the up. Closest, middle, furthest). While moving forward, I moved the machine steady at about 1 inch a second or slower. I know that seems slow but look at it. It works well. Then on the backwards pass/pull, I moved at the same pace where the carpet was heavily soiled, but where it wasn't pet stained I went about 3 inches per second. This may sound slow but consider that you have to let the solution get into the carpet and let the machine do its job. No product can do that if you rush through it. And dont force it. Let it do it job. You just steer it and place solution accordingly. On the forward pass, I held the trigger to spray the entire distance, then on the backwards pull I only held the trigger where stains resided. The suction is at the very front of the unit and collects everything on the backwards pull. Where heavy solution was applied, another slow pass, without pulling the trigger, will gather up about 95% of the moisture. That said I did make 2-3 passes forward and back with applying solution where the stains were prominent. Which was a strong majority of the hallway. The first pass really did the job better then great but considering the nature of the stains, I wanted to be more than thorough. This hallway measures about 4' wide by 23' long and took about 1 to 1 1/2 hours. But, boy was it worth the time, money, and effort. The bedroom is my young daughters who struggles still with door knobs and thus her room is open for her, by which the pets in the house took full advantage. Still not good but they did keep most of there spotting to the hall way. Her room was just as, if not more important than the hallway to get cleaned for her benefit and sanitary health.Once I was done with the cleaning process, I emptied the dirty and clean water tanks and rinsed thoroughly. Then I put about 1/2 gallon of plain water (No solution) in the fresh water tank and ran that over the clean floor by spraying the water just as if I were cleaning the floor. I didn't use the full half gallon. I ran enough water through until I felt the solution was pretty well cleaned out. Probably a total of 1-2 minutes of total trigger squeeze. This was to allow fresh water to run through the machine to clear out the solvents in the lines that carry the solution from the clean tank to the sprayer nozzle. I can't confirm this was or was not long enough. Just going on experience to avoid damage of the unit while in storage. Once that was all done. The carpet was completely dry by the time we went to bed. So probably 4 hours or less.It's been 2 days since I did this and spots have NOT magically returned. This is a major win. I will try to update this post after a total 1 week has passed to see if it still holds. If so, I'd call this an absolute winner, where other products have completed the job or professionals have left and within two days spots have returned. That has not yet occurred in this case.Also, to resolve the pet issue, we placed a very solid metal baby gate to block the dogs from going back upstairs without us, during the day, until it's all our bed time. We work from home, so the dogs hang with us throughout the day. They sleep. We work. They have always and continue to go out at least 8 or more times daily or whenever they sit at the door and whine. Love 'em, but now we can live easier without "never disappearing" pet stains. We've been renting in this house for almost a year and in our previous home we sold, we had hard floor, for a reason, and will do the same when we buy again in the next 6 months or less. Clean floor + landlord = No loss.Happy research hunting and good luck with your floors.