Henry from optionautoimports actually emailed me immediately yesterday when he received my return and included a picture of my pipe right next to the pipe they should have sent me. We got back in touch over the phone and he's sending me the correct pipe.
Henry is a good guy, and he definitely knows what he's talking about, another guy who works for him made the mistake when shipping. But he's actually been a Supra owner himself for several years.
I withdraw my initial warning, at least partially... Just beware that you may be caught in a similar situation, so reinforce to them that you expect the pipe shown in the auction.
As for build quality, as I stated before (and as fstlane stated above), the build quality seems pretty high quality, and the welds are very well done... My only concern is that I don't believe the pipes are SUS-321 as advertised in the eBay auctions... I question this because the ZW site itself advertises the usage of SUS-304...
Also, parts of my piping were actually magnetic, indicating a ferritic structure... While this doesn't necessarily mean anything adverse, I'm guessing that it's not a very high quality stainless... I'm sure it's sufficient, but all of the stainless steel exhaust parts I've purchased for my past vehicles have been non-magnetic (higher chromium and nickel content)...
