I've seen it as well, my reason for watching it was because it's a noteworthy animated film, and I thought it was decent enough to be worth watching once, but agree with a lot of your criticisms, Ralph Bakshi is an interesting animator but his films tend to be lacking something or another, thought I've not seen many of them. Have you seen American Pop? I quite liked that one.
Ah, I know the one you mean, but I've not actually seen it - all I really know about it is that they based the look of one character on Grace Slick from Jefferson Airplane. I'll certainly look out for it, but Bakshi's films don't seem to come up on VOD very often. The only other one I've seen was Fire and Ice, which was interesting for the heavy use of rotoscoping, but it was kind of forgettable otherwise.