My old 2x2 interface didn´t have a merger function so I needed to upgrade. the CME U6 MIDI Pro ticked the few boxes I had, but I was surprised by the routing capabilites of this tiny box.
The software can look complex, but just clicking around you quickly get an idea of what you can do, and it´s impressive for the price and the size of the hardware.
The only negative thing I can think of is that the usb-connection on the box feels a little bit flimsy.
Not excessively, but I can see the connector getting worn out over the years if moved around too much,