Before anything: - 3000 for klonky klong Novilation implosion 61. Their Midi Remote´s are +/- in terms of keybed, but don´t expect too much, they are playable, but not great.
If you know how you like most to play, what you would like to do and wasn´t able to so far, knowing this will, help (you) in pin down what kind of model of masterkeyboard you need/want.
My main concern wouldn´t be faders and controllers, but the keybed in first place, then keyboard split zones, midi channel switching control, dual midi out, onboard multitrack sequencer, some rotary encoder, maybe an arpeggiator.
My favourite non-hammer action keybed is the SQ80, followed by XP-30 and QM Cyber6, on these I can express most of my playing. After this only hammer action keybeds can “help” me.
The SQ80 has a good keybed with polyphonic aftertouch, very rare, but then to control different midi channels…well, not so master keyboard.
The XP-30 keybed is as good as the SQ80 but has only monophonic aftertouch, the plus is you get a ton of sounds extra, and the XP30 sounds good, as full as a xv5080 not like a thin jv2080. You can switch between 16 parts/midi channels quite good, but not really masterkeyboard like.
The Cyber6 has a great keybed and the best control over multi channel midi, please read up on it on the net. (((On a QM Sirius is where I sketch most often than not in no time my musical ideas together. Keybed is simple, only dynamics, no AT, not klonky, but it has the best performance/seq/arp control bundled with a +/- soundengine. On a side note: I hate computer sequencer.)))
From those 3 or 4, the Cyber6 as a (no-hammer action) master midi controller is unbeatable, unless you build your own (eierlegendewollmilchsau) controller . . . but then you spent lots of time to plan and building instead of making music and having fun, well planning and building is fun too
If you are up into full hammer-action keybeds, Casio might sound cheesy in first place, but they actually have very good feeling actions, not equal to a Rolaundry Digi Piano for $10-15K, but for around $1000 top hammer action+8Track-sequencer+master keyboard controller functions: PX5s.
Or Rolaundry xv88 or A90 also played them until they gave up, sold years ago.
I don´t know!
It depends on what I wrote in 2nd paragraph and on how much you would like to spend on it.
Best all around, not too expensive, very easy programmable (over Combutar), good keybed, would be anything from Novilations Remote series, mk2 or mk1 both good, great for multiple control templates available through rotary encoder, for VST super easy, for my hardware synths I have to program more of them into the my Remote 37 SL.
Other alternatives: Yamihuha KX series, Edipopel PCR series, the new Rolaundry A800pr0 or A 88