The point is that either one can look better than the other, but in Red Dwarf's case the CGI has always been a bit subpar. While the models may not be able to achieve the level of realism that good CGI can, they're far superior to the cheap CGI we'd be stuck with otherwise. Slainmonkey's frame comparison illustrates this perfectly. Honestly, I couldn't disagree more with people who say that models have a sense of realism that CGI can never achieve. To accept that, you have to ignore any special effects from big budget films and TV which clearly surpass anything models could achieve (Avatar, for example). That's not to say I dislike models (I was overjoyed to hear they were returning to RDX), but saying they're always better than CGI is just your nostalgia filter acting up; the same reason people claim all the cartoons and video games made nowadays are tripe compared to what they had as kids.