Fader controller to complement the CC-121: Anyone using one?

I’m very happy with my CC-121 as a single channel strip, but want to add a couple more basic faders to my setup for mixing - really, just a bank of faders for balancing levels, and then using the CC121 for getting in-depth on a track-by-track basis.
Has anyone had any luck with using another controller alongside their CC-121?

What I’m most curious about is how they interact; the CC121 follows your selected track, but what happens with the other controller? Ideally, I would hope it would also follow; I assume that the tracks would overlap (one of the channels on the controller would be assigned to the same mixer channel that the CC121 is controlling), but I can probably tolerate that. Probably.

Anyone using a setup like this?

I am considering exactly the same. I have looked the X Touch Compact.
There a very good video on YouTube about it tho.
http://m.music-group.com/Categories/Behringer/Computer-Audio/Desktop-Controllers/X-TOUCH-COMPACT/p/P0B3L

I am thinking about buy this one. Considering the case.

More user experience would be welcome