BopPad and KBoard...
As ever, KMI has their own ideas about performance use cases, and they've shaped the MIDI output accordingly. I usually disagree with those ideas, and their products thus frustrate me.
BopPad is very responsive rhythmically, but as a control surface, limited.
They track one touch at a time per quadrant. Press a second finger into the same quadrant as an existing touch, and that finger's ignored. So, four note polyphony, tops.
Data provided is note velocity, pressure, and distance from center.
No XY or radial coordinates were ever promised, and when I asked, there were no plans to include them. This could change, given sufficient interest. I'm sure it's just firmware.
(why care? well, in the top two quadrants, distance from center is enough for an app to identify and respond differently to whichever finger triggered a given note. bottom two quadrants, no chance -- your hands just don't bend that way.)
K-Board... the "MPE for serious keyboardists" philosophy is going to set the movement back a few years.
There's simply no mechanism to bend from one note to a different note. Pitch bend is, to their mind, about vibrato only.
Keith's suggested workaround was to increase the range that each key will bend. That's... horrifying.
It's a musically limiting solution, because whatever you set it to is still a fixed interval, with no reliable way to stop at a different note along the way.
But more than that, it breaks the "x = pitch" analogy!
(If you bend up an octave without moving your finger off the key, the next pitch up is 11 steps lower. What fresh hell would a glissando sound like?)
That decision... I get why they did it, but I wish they'd instead gone with the standard established by Continuum, Soundplane, Linnstrument, Rise, Blocks, and any number of iPad apps.
I didn't cancel my order, because I'm arrogantly convinced I can fix it in max. But I have to say, I'm a lot less inclined to put in that effort, with so many options that already work.