As far as I know, Skyservice, LTU, Swiss, US Airways and VG (Delsey) operate the A330 with Pratts. There may well be others too - I am sure others will tell us who they are. I fly it with the Rolls engine - no problems there I can assure you!!!! Some colleagues of mine flew a Pratt powered A330-300, and they said that while they didn't encounter performance problems as such, it certainly didn't have as much in hand as the Rolls. I'm sure others can elaborate.
Cheers
