We have had this for a year.  You can't flip it but you can rotate 180 degrees.  Slight off gas smell for the first day.  I am sensitive to smells and it didn't bug me. We are now looking for a new mattress. My back and hips kill me.  When I sleep on interspring , I have no issues. This does not have enough support for me. I sink into it and it curves my back. We are passing it down to our son and getting a traditional mattress.