That's not specifically a W/T mirror; that's the standard folding mirror used from 1992-up, available in non-power and power adjust. The aftermarket copies of them are garbage. The factory ones are pretty good. Can be tough finding originals in good condition these days, though. If you look on the bottom where the mirror mounts to its base, the OEM ones have torx screws; the aftermarket copies generally are phillips head - quick way to tell 'em apart. The copy mirrors generally have a looser fit and the glass vibrates while driving. Also on any of them used (original) or new (copy) check for flop in the fold joint.
As far as 454SS mirrors being crap, lol, I guess? The commonly available plastic copies of them are crap. The original metal ones are nice. There are also metal copies that aren't bad; I've directly compared them and those were a pretty damn nice copy. I think they were TYC. Now, if you mean how useful they are? Yeah you can't hardly see a damn thing out of them. But they look great.
Richard