I'm quite fond of 'playing' my Mackie Onyx, I think the problem with pots vs slides is the smoothness of the movement and the pots on this are quite gentle.
As for eurorack mixers, the one module that is severely underrated is the Mutable Instruments Frames. It is next on my list of purchases, but there isn't anything else quite like it. Programable, CV-able, sequential and more. I honestly don't understand the rush on companies putting out eurorack mixers when they don't offer anything more than a couple of VCAs would.