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)

**UPDATE** The Leslie insert effect works just like you want it too. The screen is pretty, and the slow/fast switch is gradual, and authentic. Pity that so far, the dedicated button will go to waste unless we can assign it to something else. If you use the joystick, you can get a gradual change, as well.

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?