I can't say I knew such a thing existed until it was posted here but basically I think wolf is known for cheap steel case ammo generally.
A sub $500 piston upper is in the real bottom of the price range and leaves me skeptical and a little scared to be honest. Basically piston AR's aren't standardized so unlike a basic mil spec derived part I ASSume its something that Wolf dreamed up on their own and isn't that well deployed to have the bugs all worked out. With a piston ARish thing you really want good quality as you 100% depend on the maker, I would think a SCAR for instance if I wanted that.
I'm not a gun snob, still wouldn't go as low on the quality scale as PSA though, but a PSA upper is a known quantity, they work good - if you want cheap that's a good place to start. Aero isn't much more $$ and is a lot better IMO.
Add: come to think of it, if I wanted a basic iron sight flat top I would definitely be looking at Stag first, real good authentic no frills AR parts and they support their stuff well.