Purchased January 2019--The only real negative in the experience was shipping time. I think it's ridiculous that an in-stock item doesn't even go on a truck for more than a week after ordering just to coerce people into buying Prime. The mattress itself though--a winner.Taped to the mattress when you open the box is a zip-lock bag containing a tool that is basically one of those safety-type letter openers (pic), to cut the plastic off and avoid damaging the mattress from using scissors to open it. There are two layers of clear plastic wraps--an open-ended "tube" around the outside of the rolled up mattress, and once that is removed and the mattress is unrolled, there is what can best be described as a vacuum-packed heavy-duty shrink wrap around the mattress itself.One surprise was that the moment the outer plastic was off, even with the inner wrap still on, it started "inhaling" air with an audible hiss. It did not actually begin to expand though until the inner wrap was off. When the inner wrap was cut with the cutting tool, I needed to get it pulled away from the mattress rather quickly to avoid having to lift the entire mattress to get it out, because by the time I got the inner wrap off, if already looked like a mattress and not the 2 inch thick pad it started out looking like. Within 10 minutes it was already 9.5 inches tall (pic), with no sagging corners as mattress-in-a-box reviews sometimes report. There was a bit of off-gassing when I first opened the mattress, rather like the sweet/chemical-y smell of new carpet, but it was completely unnoticeable by the time I actually went to bed about 3-4 hours later.If there was anything I thought Lucid could have done differently, it was that the mattress seemed to me to be rolled up backwards. I assume this was to allow the top layers of foam to be on the outside, to protect the springs fron damage during shipment. Just as in the video reviews I have seen, if you simply lay the mattress down and unroll it down the top of the base or foundation, the mattress is upside down--I had to flip a 100 pound bulky King mattress by myself. If you lay out the roll so the the top side is up, you have to unroll it by pulling the mattress roll from underneath rather than simply rolling it out, and the roll is heavy enough that such a method may not be practical without damaging the mattress.Now for the mattress feel. The mattress top feels like a regular memory foam mattress rather than a hybrid; I have yet to feel an inner spring from this mattress digging into me regardless of position. Edge support is much better than I expected for a foam-topped mattress -- there is sinkage along the edge when you sit with feet on the floor, but I do not feel as though I am going to slide onto the floor. I also like that there is no steel wire digging into the back of my leg as I sit on the edge.I am a 6'2" 250 pound individual with chronic back issues who is primarily a side sleeper. In the past I have had trouble with mattresses giving me pain in my shoulder and hip, causing me to interrupt my sleep and turn over frequently in the night to relieve the pressure, and then the act of rolling over causes me back pain.After my first night on the mattress, I noticed no back, shoulder or hip pain either during sleep or upon arising, and do not recall turning over at all. A really good night's sleep. It is a different feel than I am used to, but I expect that my sleep will get even better as the mattress becomes a more familiar nighttime nest.Being a good sized, guy I probably sink into the foam more than a lighter person would--they might experience the mattress as on the firm side of medium, whereas it seemed to me to be just on the plush side of medium. It definitely was not "hard". I was concerned that my hips would sink in more than my shoulder and I would feel like I was sleeping with my feet downhill, but that was not the case. The sinking in seemed very natural and felt like it kept my spine in alignment as I lay on my side. At no time did I have the sensation that the mattress was swallowing me up (perhaps due to the innersprings), and I never experienced the overheating that some memory foam sleepers report. I was very comfortable, temperature-wiseI like the idea of the charcoal infusion to maintain freshness in the top layer, which has ventilation holes down to the second layer, which is an aloe vera gel-infused layer that is supposed to wick moisture vapor and heat away from the sleeper. All in all, there are 4.5 inches of foam between me and the springs (compared to one inch or less in a conventional innerspring mattress), which is probably why I never felt like the springs were pushing against my pressure points. The top layer of foam is also more responsive than typical memory foam, more like latex, making it easier to roll over without feeling like the mattress is resisting you. It sleeps like a mattress at a high end hotel.If anything changes as time goes by I will update my review, but right now it feels like the most comfortable mattress I've ever slept on.July 2020 Update--I have now owned the mattress for 18 months, it still looks and feels new--no sagging on the edges or in the middle. I do spin the mattress around horizontally about every other time I change the sheets, to even out the wear, but so far I'm not noticing any wear. I'd buy this mattress again.October 2021 Update--in a few months the mattress will be three years old, and I still would buy it again. The memory foam has softened a bit in that time so I experience the mattress as a true plush in firmness, but there is no noticeable foam sagging in the areas I sleep in (a common problem with memory foam-only, non-hybrid mattresses) I still cannot feel any springs poking me through the foam, and as mentioned, I'm a big guy. Considering the average lifespan of a mattress is designed to be about 5 years it has held up very well.The cover has had a few minor spills (young grandkids dropping their "sippy cup") and the cover spot-cleaned very well. IMPORTANT---please do not EVER take the cover off the mattress expecting to launder it--the zipper seam is for cover installation at the factory; it is not designed for consumer removal. If you do that, the loose fiberglass fire retardant inside the mattress will go everywhere--this is common to most memory foam mattresses, so it's not strictly a Lucid issue)If this one ever wears out, which it shows no sign of doing right now (late 2021), I will certainly place the mattress at the top of my list of possible replacement candidates.