The Keilwerth SX-90R is a fantastic horn, but I wouldn't overlook the SX-90 without the tone rings either. The problem with the tone rings was never as severe as it was made to sound, but Keilwerth has taken extra care to make sure that it is no longer a problem. I believe your chances of being struck by lighting are greater than purchasing an SX-90R with warped tone holes! Compared to the Yamaha and the Yanagisawa, the Keilwerth has a more vintage tone, especially the R. If you are looking for a sax that sounds like a classic 6M, with a more modern feel and features, the SX-90R is as close as it gets. The Yamaha 62II is a great horn, and a great value. The 62 has a nice sound that is very neutral. Depending on the mouthpiece and set-up, they can really scream or sound great for classical. The Yanagisawa has one of the nicest actions. Try them all! See which one you like best!