Edit: I’m assuming you’re talking about comparing the keyboard actions (Behringer vs. the Korgs)? The synth engines of all these instruments are pretty different, that would be another discussion…
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I’ve got an early Deepmind 12 and a 3-octave Wavestate. (Also an Opsix, which feels like the same keyboard as the WS.)
I like the Deepmind keys better (and they have aftertouch!). They’re a relatively light action, but comfortable to play. I guess someone who’s a more serious keyboard player than me could get frustrated if trying to play fast licks, because the DM12’s keys don’t “snap back” as quickly as some other synth action keyboards I’ve owned—but this is trivial for me, I don’t play fast. The aftertouch response on the Deepmind is nice, not just all or nothing.
I dislike the keyboards on the Wavestate (and on the Modwave, which I sold), although they are playable. Usually I like light action in a synth keyboard, whereas the WS keys feel light but somehow unsupportive, like there’s not enough springiness. My guess is they’re well-made (I’ve never broken a key), but I hate the feel more than anything else I’ve owned.
Just one opinion. Neither synth has an amazing or totally unplayable keyboard, we’re talking nuances here.