Great points Harold, but as long at it is an Arrangerkeyboard containing huge amounts of autoaccompstyles, this is in my mind a machine designed to OMB, With some adjustments it will fit into Trio or Duo gigs as well. Specially when see that styles are very (already well known) song orientated. Then it should sound more "alive" out of the box.
Now we se that Yamaha has lifted both (or at least try to) Tyros 5 and Genos more into Workstation and Songwriter category, we might expect to see further migration in that direction in the future models.

Still, if anyone ask me, Genos is the best in category from Yamaha till now, also how it sounds .....
... but if only money talks, to me the best deal probably will be to keep T4 and add PA4X-76.:)