I've never come around to seeing TPM as a horrible movie, but to be fair it's got so much cultural baggage around it that I don't think I could ever watch it again without the baggage hanging over my head, so I probably won't.
At the time, I thought the CGI and backdrops and all were the best visuals I'd ever seen in a movie and was stunned at the $115 million price tag, figuring it would have cost far more. A couple years later I decided the first LOTR movie was better. I don't know how that would hold up today, but I do know that since I continued watching ROTS afterwards, some of the backdrops in that movie have aged rather poorly (the ones where Lucas has loads and loads of little computer generated characters walking around in the background like extras.) That chase scene with Obi-Wan riding that lizard thing on the hole-planet is way too blurry, and to think millions of man-hours were probably spent on making it. So I'm guessing the same would happen with TPM; when Alpha Hammer was still posting here he said he watched TPM with his kids and could confirm that the visuals were utter crap now.
As for ROTS, the primary response to it at this board that I remember was Rich Bunnell going "deuhrrr, fake-looking lava. Whoa, OMG." Which was pretty par for the course at this board in 2005!!