First let me explain why it only got 4 stars.1. It does smell like really strong nail polish2. It was cut in a manner such that it was actually 1 inch short on one side of our mattress. Not a big deal, but we paid a lot of money and we expect to get our money's worth.As Far As Other REviewer's complaints:I read through lots of reviews on lots of similiar products and especially on this product. I can say that the smell on our mattress is not so bad that we didn't sleep on it the first night we had it. I only aired it out for 6 hours on my bed and then we slept on it that night just fine, but it is winter and cold, so that may have something to do with it. I can also say that ours is ventilated, like it claims. It also did fluff out to the full 3 inches. Last but not least, the mattress topper does not make me hot. It's been cold the last few days because of the weather and I have also been cold in bed, piling up the blankets. I kind of wish it insulated heat better, but that's not really what it's made for.Good Stuff I likedMy husband, who only sleeps like 5 hours a night and usually just tosses and turns says that he slept so good he felt like he could have stayed up for days. So this is definitely saying something, becuase he's such a light sleeper that he usually never sleeps well. And he did, stay up for almost half of the next night just because he slept so well the first night and he said again that he slept really well.I can say that for years now I haven't been sleeping well. After I had my kids, I always had to keep tossing and turning becuase my hips would ache and my arms would go numb. So far I have not experienced that problem anymore on this new mattrress topper. I slept so good last night that I woke up refreshed for the first time in a very long time. I didn't feel like I needed that extra 15 minutes anymore, I just woke up and was actually awake, and not really still tired, like I usually am. So I am definitely impressed. It is extremely comfortable. I'm glad we made the purchase and I plan on buying two more for my children's beds as well. This is going to add quite a few more years to mattresses that we previously thought we would be replacing this year, so we saved a ton of money. We're so pleased that we are contemplating never buying another mattress and just continuing to buy these mattress toppers. It's a much cheaper (more comfortable) alternative. So I plan on updating this review in a few weeks, then a few months to let you know how it's holding up. So far so good.Update At 1 Week of Ownership:It's been a week or two now that we've had the topper. This smell was pretty much gone in a few days. It's still as comfortable as ever. I have woken up wide awake since we got it, which is definitely an improvement. I used to wake up tired in the morning and drink lots of coffee all day to survive till bed time again, but now I wake up with energy and it's really nice not to feel sick every morning. My husband still says he sleeps great and I have seen quite an improvement in both of our moods. I will say, that it does slide, and I wish the product came with a protecter sheet thing that attaches to the bed to prevent all the sliding. Also, I am still a little dissapointed that it doesn't quite fit our bed becuase when it does slide, I somehow always end up with the 5 inches of bed instead of topper! But I will still be buying a few more for my kids. A really big plus is my decrease in caffiene consumption :)Update at 1 Month of Onwership:It does take some time to adjust to the mattress topper. So I would say if you seem to not like it within the first week, just hang in there, becuase it you will need to recreate your whole sleeping habits. I used to lay in bed for hours before falling asleep, now I fall asleep within the first 30 minutes. So then I was waking up really early fully rested, yet it was still like 4 am! So I had to start staying up later to get up in the morning at a reasonable hour. Which made me cranky for a while as I am not a night person. Some of the reviews have talked about back problems, or turning over and waking up constantly, I'd say if you experience any uncomfortablness or awkwardness, that you just give it at least a month before making any final decision about it. It still slides around a lot, which is super annoying, but other than that, it continues to be one of the best purchases I have made lately.