Small, cheap, and especially able to run the sysex messages to my old D110. To my knowledge, only the Edirol PCR-x00 controllers are capable of properly. It was my first test.

Other than that, all the connections usual, and tons of knobs.
The keyboard responds to the pressure: mono aftertouch, but not polyphonic.

UTILIZATION

The keyboard is okay, nothing more. Avoid pressing too hard when you want aftertouch effect, because the keys fall apart! (You really insist ...). Generally, the finish is good, but everything seems lightweight and extremely resistant to book the studio.
Programming is not complicated as long as you read the manual, not complicated, but not intuitive. The tiny LED display does not help. The PC software is simplistic, but goes a long way. Obviously, a good knowledge of MIDI codes is recommended.
The manual is correct, the procedures are detailed.
One big negative: only 15 patches in memory. I use 12 to drive the D-110!

OVERALL OPINION

I use it for several months. I have not tried others before, but I read the manuals for many models, and only the PCR-x00 are able to control a machine like the D110.
Considering the price and my usage, I am perfectly satisfied.