Took a couple of days to get used to. We did let it air for the full 48 hrs. No smell. Stays put on the bed. 
Took a bit of getting used to. 
After 3 days we love it! So comfortable no more hip or shoulder pain. 
A little more difficult to move around in bed, but no big deal as we sleep longer, better and dont move as much.
Sleeps fairly cool. Pleased so far.