If you like what you hear from the Tyros2, and you cannot hear a significant difference between the T2 and the T3, there is absolutely no reason on earth to upgrade. Additionally, I can almost guarantee that within the next six months someone will have converted all the new T3 styles for use with the T2, S900 and PSR series of keyboards. They may not be exactly the same because of the difference in sound engines, but there will be enough for you to have fun with.

Good luck on whatever you decide upon,

Gary