My feelings on the matter of which is worse, AOTC or ROTS goes like this. AOTC is by far the worst quality of the three, filled with the worst ideas, and the weakest plot. It is a really, really awful movie. I feel that ROTS stands slightly above it on a quality scale, but it is also the home of some of the most pivitol and important parts of the entire SW saga, and all these things, and I mean absolutely every one of them, was pulled off incredibly poorly. To me, this ultimately makes it worse than AOTC. There was more at stake with it, and the loss was greater. Despite the fact that the Clone Wars are suppose to be a huge historical event in the SW universe, the entire movie was essentially filler (as was TPM). Revenge of the Sith was the main event, it was what the previous two films were building up to, and it fell incredibly flat. Beyond flat, actually, I feel it left quite a crater.

Could be wrong, but when Ash mentioned Order 66 being the only good part of the film, I think he was probably referring to the quality of the montage. It was rather nicely done. If I had actually cared the least bit for any of those retards in heavy makeup, it probably would have been a very powerful moment in the film.