Let me preface by saying - there may be many hidden assignments available to the buttons that I haven't gotten to yet. This is a sort of "triage" assessment.

Things I like:
1) you can assign the real time knobs to be volume for any number of sounds/styles/songs. I chose #1 to be songs, bass and drums, and #2 to be keyboard sounds
... make for easy subtle changes during a song. Balancing is easier this way.
2) you can tell the knobs to control the volume/EQ of the "aux in" input, so I may not need a separate mixer for my iPad tracks. TBD
3) The guitar based sounds (esp. w/overdive) are great. Don Mason has used these for years, but I'm the new kid on the block with guitar sounds as a rhythm instrument.
4) Mixer/FX/EQ section is very easy to navigate. Always was, and I missed that. The key feel kept me from enjoying this feature for a long time.
5) It's not the Tyros/Genos keybed, but it IS much more playable than previous PSR offerings. In fact, I predict most players will be comfortable with this.
6) I like the "load next" in the song player. Korg doesn't do this, but to be fair - the dual player in the Korg is way better. Still - with a slight workaround, this is good.

Things I don't like:
1) The Leslie sim is terrible. Like Donny said - it's all or nothing, and actually changes the volume of the sound when pushed. Unless there's a buried menu item that addresses this - it's unusable for me (by no means a deal breaker. You can use the aux outs, and route to an outboard piece if organ is your priority)
2) I haven't used a sustain pedal yet, but I remember lots of sounds that don't respond to the pedal (organs, strings) in past years - I hope this is a settable parameter. I like all my RH sounds to sustain to free up my hands to perform other navigational tasks.

So.... 6 to 2 - not a bad start, huh?