Hi Joe,

The T4 drums are sooooo much better than previous models. You have many more choices to choose. PLUS, you can now create your own drumsets with custom sounds and samples; although I admittedly have not had to do that as yet. The OS in the T4 is pretty much the same as the T2 with some minor exceptions. The entire keyboard, however sounds so much different from the T2. I went from the T2 to the T4 and the sound difference is amazing. The vocal harmonizer is much more powerful and capable.

I too had the Audya 4 and 5 and I returned them for the T4. A decision I have not regretted for ONE minute. As a matter of fact, I'm having a blast playing the T4; moreso than than any of the previous Yamaha's (PSR610, 9000, T1, T2) or Korg Pa2xpro, or Audya 4/5.

Good luck with your decision.