Sorry, but Malletkat and Xylosynth both are woefully lacking. I suppose they can technically do what I was asking for, but the shortcomings are pretty severe.
a) user-friendliness is almost non-existent (slightly less so with the Malletkat)
b) comparatively pitiful internal sound banks/no internal sound banks at all
c) I have yet to find a model that actually approximates the feel of a keyboard. Also, 4 octaves max, and no terraced keys ever? Really?
Yeah, I’m being super picky, but really, what is the point of making a MIDI interface keyboard percussion instrument if you have to relearn everything just to play it correctly? There’s no reason for it. It’s not keeping prices out of the stratosphere - obviously you don’t need to use the high quality Honduran rosewood or include resonators or even a frame, which is approximately 80% of the cost of an actual marimba. You’re paying for the electronic side of things, which the piano MIDI interface world has perfected to an art form.
I’m not saying the models on the market right now are worthless, any more than I would say a 49key unweighted piano synth is worthless. I’m just disappointed they haven’t come out with something a little more… well, more.