Yeah, I pretty much agree. Even though there are "grand" visuals as you said, there's not much that really stands out and is memorable to me. I feel like the design of most objects are ok, but nothing special. Droids, ships, weapons, environments, etc are just "meh." There's nothing really iconic (to me, anyway).
I find myself watching the PT webisodes every now and then because I'm curious as to what the process was going into these movies, and where things went wrong (I know, strange thing to waste my time on considering I don't enjoy the PT at all, but...). I'm probably reading way too much into this, but I find this quote from design director Dough Chiang re: the design of Star Wars to be telling:
When I saw Star Wars, I was really blown away but I was actually kinda like, hmm, there are certain things that I didn't like about it. But the great thing was I went home and I kinda drew, you know, my version of the X-Wing.
My view as a diehard OT fan is, what's NOT to like about the design of Star Wars? Especially the X-Wing! I'm not saying you have to like everything about the design- but it seems to me you'd want someone who loved damn near everything, to try to stay consistent with the OT.
Of course innovation and thinking for yourself is very important; you don't just want someone to copy existing designs and have everything look derivative, but you do want some consistency of design. But I don't think I'm explaining myself very well. I guess what I'm trying to say is, based on that quote, it sounds like Chiang didn't quite like the OT design very much; no wonder WE don't like what ended up in the PT. If that makes any sense.
The quote starts about a minute into the video:
http://www.youtube.com/watch?v=Gx7YSByPI8I