Actually yes. I have hear some new sounds for example the acoustic and electric piano's, guitars, a great sounding new harmonica, new clarinet and a few others.

If you listen to a Yamaha Tyros 2 and a Tyros 4 I hear a Yamaha. Yes there are a few differences but you can hear it is a Yamaha. Same is with Korg. Same is with roland. Same is with Ketron. So ofcourse the PA3x will sound like a PA2x only better.