I purchased this unit to use for mixing in Reaper. It's functions are fully customisable using CSI for Reaper, but it will also work well out of the box using the MCU protocol
Mechanically it's well built and durable, you could throw it down a flight of stairs or two.
The faders tend to squeal when following automation. If you're working from a well treated quiet room this can be incredibly irritating.
Mechanicals: The faders are jittery.
This seems to be a trend with all available controllers currently. I imagine any improvement of this would push manufacturing costs and the price of the unit up significantly.
Displays:
Viewing angle of the LCD displays is poor, only legible when you are looking directly down on them, RGB colours not supported using Reaper and the MCU protocol
Overall it's good build quality and value for money, the pro's outweigh the cons.