We just received this Twilight mattress and  have waited  until day 3 for it to reach its size. 
And after a nights sleep we can not say enough good about it.  First off we did not detect any odor and it was easy to set up.  Packaging was sturdy.  
Its comfort level for a back and side sleeper is perfect.  And even more important it is a cool sleep with the gel. 
We were somewhat leery about foam mattress style; however this product will make you a believer.