Behringer X-Touch Extender

Trying 2 Extenders together as one 16-fader controller, without having the main X-touch Control. I did not see anyone with this configuration but after trying it can say it works very well. As I already had numerous controllers I just didn't need the extras -- only each motorized fader/dispaly/encoder/mute/solo.

This setup takes a bit of messing in the daw to assign each unit because it has a problem recognizing multiple identical devices, so far I've tried it with Logic and once it is set then tracks 1 - 16 work perfectly.

Very affordable, the price is worth it even if the faders are slightly noisy and occasionally a bit unpredictable. I'd happily buy a 3rd to make it 24.

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.