Mostly annoying, largely because it looks very stuttery to me. When it’s integrated seemlessly, it’s fine (more often the case for background related cgi). Even in something like chainsaw man which did it pretty well I still found the cgi in the action scenes grating, it took me out of it a little.

Full cgi i mostly get annoyed at the stutter, and I like the style most full cgi anime have a lot less than most 2D anime.