The "bad CG" is pretty much limited to the first season. From about the end of the second onwards they'd pretty much got it all sussed out.
Some people just like to whinge but the fact is, even 'The Gathering' for all it's limitations, at the time featured the very best CG work seen on a TV show (other shows were still filming miniatures.) Of course it's crude by modern standards, but then how can it not be?
Yeah, it was 1993 after all. That's like saying that the special effects of Star Trek: TOS suck. Well, they do compared to today (emphasis on "today").
But maybe it's a bit different for people (like me) who originally watched the show in the mid-90ies.