We bought one of these (for the same price) maybe not quite a year ago.
Just rotated it last week, and still have yet to feel any indents or weakness in the foam.
I like a firm bed, and this foam is just right between firm and snug (the foam is more giving as it warms up and conforms to your body). My wife doesn’t like it as much, she preferred our previous pillow-top, but she’s a lightweight at 130 pounds, so maybe this is a bit too firm for her?
I needed it for my back, though, and it has helped.