UGH! Don't even get me started on the MPK88,
I mean, they apparently could not make a keybed that doesn't have manufacturing defects to save their life.
True story; I tried six different MPK88s and every one of them had either a white key on either end that was mechanically defective or they had at least one black key which was electronically defective in that if you hit it rapidly it would cut out. I put way too much effort into trying to find an MPK88 that would work and finally I discovered that the Keylab 88 was coming out so I decided to preorder that instead.
I don't even know who the hell makes their keybeds, I suspect because it's not a named keybed, the MPK88's keybed might have been purpose designed by AKAI in-house.
And yeah, I agree with the rest of your assessment, there are alternatives to the keylab 88 or mpk88 but they all wind up being compromises... like Kawaii with the VPC1 quite literally just took as much of a piano action from an actual piano as they practically could and just stuck it in a box and from what I read in reviews, it feels perfect, but absolutely no encoders/faders/pads, hell the damn thing doesn't even have a pitch or modulation wheel, it really is like an amputated piano.
That's pretty much the gist of it from what I can tell, there simply isn't an 88 key controller that 'has it all'. What I've seen some significantly wealthier people do is that they find an 88 key workstation that has all of the controller features that they want and they just use it as a controller essentially, but that's a very expensive solution.
Arturia, if you're reading this, I wish you guys would release a 'Super Keylab 88'. A keylab 88 but with one of Fatar's really nice wooden keybeds AND motorized faders, last 88 key controller I ever buy.
EDIT: I looked it up... I'll just say that the VAX MIDI looks interesting... I mean, I have fixed a lot on a lot of cars, fixing up a car and selling it is actually how I got the money for a Keylab 88, and by comparison assembling a VAX MIDI doesn't look that daunting at all. It might be a viable business model for them because one thing to keep in mind is that a lot of people who build professional studios choose to save a lot of money by buying the parts for an audio console and putting it together and soldering it themselves, so they might have a market for an 88 key that takes 4 hours with an electric screwdriver to assemble.
One thing that's interesting about the VAX MIDI compared to the VPC1 is that just like the keylab 88, it is flat topped, so there is no reason someone couldn't just get some supplemental controller devices to get all the switches, pads, encoders, and faders they wanted. If I had some real money to spend then I would probably go this route, I mean, it's kind of what I'm doing right now, I use the keylab 88's "shelf" to put on a Quneo and a MIDI Fighter Twister for supplemental controls.