I highly disagree with that statement. "Of course it's gonna lag in that respect"? Says who? Why should it lag at all? I've owned 2nd, 3rd, and 4th generation iPods, and they were all smooth as butter no matter what you did with them. So why, then, should I expect it from the latest and greatest iPod? You're saying the processors in *those* iPods were more powerful?
I've determined that it's not a question of album art, space filled, or what you have on it, but is a flaw in the device itself. I have loaded exactly one single song on to my iPod (no videos/podcasts/pictures/contacts/games or ANYTHING, just the ONE song) with the album art disabled, and it's still choppy. Can we live with it? Obviously we do, it's just very annoying and frankly I expect better.
There's always one post in these threads about this issue where someone says basically what you did - "well, what do you expect?" I expect an iPod that works at least as well if not better than it's predecessors. Unfortunately, I've never heard anyone able to describe a fix for this problem. And, like all threads I've seen on the subject, I'm expect this one will end in exactly the same way.