Pompeii is a Pink Floyd milestone and indeed representative of Waters' bass playing. I was not aware of his value classification of instruments, with which I obviously do not agree. I like his minimal playing. In Careful With That Axe, Eugene, probably my favorite PF track, he is just playing octaves but this is exactly what the song needs for its moody atmosphere.I consider Waters' bass playing on the "Live in Pompeii" video to be representative of his best work. He has a style all his own and I really like it.
Technically, he's nothing to rave about, but I think his playing is imaginative and fits the vibe of the band extremely well.
One thing to note is that Roger has stated in interviews that he actually doesn't like playing the bass and considers it a lesser instrument to the guitar or keys. He said that the only "instrument" lower than bass is the drums.
I've heard numerous bootleg recordings of live Pink Floyd shows from the 70s and Waters tended to play very sloppy with lots of bad notes, and he sometimes even drops out entirely, especially when he's singing.
I'm guessing it has to do with his apathy toward the bass. It's like he doesn't care to put in the effort for live shows. At least it seems that way to me.
I believe he mostly plays acoustic guitar during live shows for his solo work and he's quite sharp doing that with no sign of apathy at all.