Well, I can say that the yamaha sound library is very nice. I owned a PSR3000 and could not believe the sounds that were coming out of it.. The keys on it were not full size and I didnt really like that and It looked and felt somewhat like a toy, BUT sequencing and sound was awsome.. I myself am looking at the roland lineup at the moment, couldnt tell ya anything bout the kurzwell line except the name should say it all, it has been around for years and still going strong.. Good luck...