It’s still brand new and I’m trying to get use to it.  It specifies medium to firm, I’d say it’s firm, end of.  I have a divan bed, so the mattress slips if you push against it, that’s due to the bottom surface being rather shiny.  
Excellent price though, and came well wrapped and even has a special tool to help you open the plastic covering.  The delivery driver was excellent also, I was on my way back from work when he turned up.  He called me and said he would come back in 20 minutes so he could deliver my mattress.  Thank you so much. 
So if you like a firm support, this is definitely the mattress for you.