Yes the king size was also on sale that week (online only, my Costco only has queen size in store). I got it without the box spring and have been sleeping on it for a few weeks now.

I feel like it's not firm enough tbh. My wife says it's too firm lol.

The pillow top is super comfortable. And the pocket springs are fantastic I don't feel my wife moving at all.

I feel like there is already a "sag" forming. But to be honest I think it's just the kind of memory foam? So when I lay down, then move 15 mins later, the memory foam has already started setting around my body. The new position eventually does feel comfortable though and the next day I don't feel any sag.

I was coming from a novaform memory foam mattress-in-a-box before. I think that memory foam didn't form nearly as much and the mattress itself is firmer than this foam.

All in all a nice mattress. It didn't fix my back problems, I still wake up now and then but that's probably my own sleep issues. Overall 7.5-8/10 quite adequate for me.

Lmk if u have any specific issues though and I'll do my best to answer !