Good luck Bernie. For me, 3 years and counting, the 3x has been a real joy and I long for nothing more. The 4x should be everything you'd ever want.
Everything? Really?
But it probably has most things many of us will ever need to make good music.. The latest update added lossless compression to the user sample area allowing for 800 MB of user samples instead of the previous 400MB
However if you want easy to operate.... Yamaha is probably the wisest choice... Tyros 5 would also be a breat option..