This bed is incredibly comfortable from the get go. I scoured the reviews before making my decision to purchase, and I am very pleased with how reliable they were. My husband gave it two thumbs up as well. Thus far, I have had no back pain (and boy do I have a messed up back) since we started sleeping on this bed. I cannot say that of any other mattress I've slept on (save my parents tempurpedic.) In addition to the back pain, I am pregnant - this bed has been just dreamy, and I am confident it will continue to allow me to get a good nights rest throughout the duration of my pregnancy and thereafter.
The only negative is the smell - which others have mentioned. It has been several weeks and still has not completely gone away, but that's also due to the new headboard that came with a similar smell and arrived a week or so after.
I will likely be purchasing another when the time comes to furnish our guest room, I am that pleased with the product.