Ben Burtt's one of the prequels biggest faults IMO, but at least he seems to be aware of the position he was in. You know, a lot of these people have had professional and personal relationships with Lucas for decades so they aren't going to slam him in the media because then people (like us) will just fixate on it and it'll look bad for himself, but its interesting how subtle little bits tactfully slip out:
"I do feel a bit critical even of films that I've been connected with in recent times to some extent, because time and technology allow film-makers to postpone choices or not make choices and therefore you end up with less focus in the storylines and so on. I guess that's a pretty harsh criticism but that's how I see it."
Of course, Burtt hasn't worked on anything but Star Wars for the last decade.