The mattress pad expanded quickly, no foul odor, and was 4 inches in height, although it was egg crate style - which I didn't realize. It was still a good deal for the price and is comfortable. but would have preferred a more solid foam slab.
It's awesome. Feels like a million fingers massaging you to sleep. It's does sleep a little warm, which is ok for California cool nights, but not sure how comfortable it would be in warmer climates. First night we slept on it I didn't want to get out of bed. Smell was strong at first, but has gradually faded. Took about 3 weeks for the smell to be completely gone. I got two, a queen and a full. They both fit perfectly.
I would definitely recommend this to anyone that likes a soft mattress and isn't too big. My wife loves it and has never slept better. I, on the other hand love how soft and comfortable it is, but I am 6'3 and weigh 220 pounds, and after a few great nights of sleep my back started hurting(I have had back pain from mattresses in the past). My body sinks into this mattress topper, but my legs do not sink in as far which keeps my spine from staying lined up while I am sleeping. I think my wife is going to be sleeping about 4 inches higher than I am very soon, because unfortunately, I think I am going to have to sleep on our firm mattress with no topper.
I haven't used the pad long enough to rate the quality of the materials in the pad but the comfort that it is giving me is excellent. I am sleeping better each night. I started using the pad 12/27/2014 and find I rest better as I become accustomed to it. No more being poked by bad springs and woken up several times a night. I am very happy and would highly recommend this pad if you like the firmer feel under you. My back aches are improving and I really like reduced pain.