I've been in the same boat for quite a long time, let me sum it up my search and conclusion quickly:
If you're picky, there's nothing in the slab realm that will fulfill your needs as much as some cabinet style DP may do.
I also craved a slab with a good action, variable key-off, long keys, good sounds etc. The MP11 was the closest option but since I came from a CA97 and suffered myself the sliptape issue I didn't want to hear from Kawai at least for now.
Also another issue with the Kawai is that its MIDI implementation is done in such a way that it doesn't let you easily control VST (dynamically speaking), that's a huge turn-off if you're intending to use pianoteq and similar software.
After a lot of trying, Roland has IMO the best MIDI implementation to use as a controller, like it or hate it.
Options here are PHA50 and Hybrid-PHA50, same mechanism having the latter a longer pivot point (26cm) and offset pivot for black keys, just like actual acoustics have, that may not sound important but it does indeed let you think how much these guys cared about details, this offset helps have a balanced touch when playing black keys so they don't feels easier or softer than the whites.
Ended up buying an LX706, cheapest model with the aforementioned action, can't be happier with the touch, it's not love at first sight, every time I've tried it in the shop I was disappointed and thought it's out of my list, still gave it an option because it made most sense mathematically and I proved myself right. Plenty of possibilities to adjust the feeling (internal touch curve adjustable in 100 steps instead of 3 preset options).
Piano sound on this Roland is okeyish yet not enjoyable for me, cabinet makes a beautiful furniture but no mobility whatsoever, sometimes I think what an overkill just to have a MIDI controller with a good action.
Manufacturers are smart, they never trickle down their best actions to the portable segment (except Kawai with the MP11 at their time), that leaves the cabinet style market alive which is probably more profitable.
There are many nice slabs if you accept compromises, if not, the you better accept the reality and go for a nice cabinet style with good action and MIDI.
At the time I also tried MIDI response on many brands, turns out best implementation was Roland followed by Casio (GP series) and Yamaha if that helps, note-off was variable only in the Roland and one of the others I can't remember well.
Sorry for the long message, I was hesitant to write it, so much good advice from the fellas around here but I wanted to give you my insights.
Good luck,
David
P85>Kawai CA97>Numa XGT>FP90X>LX706
Pianoteq 8 Pro (all instruments) + Organteq 2
i7 4790K W11 64bits + UMC1820 + MTM + DT770 pro X
http://youtube.com/DavidIzquierdoAzzouz