I feel that ROTS wasn't a great movie. I think the whole PT really missed the mark as a whole. TPM was closest to getting it right and then it just became about special effects and whatnot. Not that TPM didn't have that but it had more of a heart to it. Lucas tried to set up characters we would like and care for. He tried new things to keep the story new and fresh. Some of these didn't work and some of them did.
In the end I wouldn't say the PT hurt the OT at all but it definitely didn't strengthen my love it like I thought it would.