Reporting back:
I got my TC Helicon Blender today, and my first impressions are really positive. The user interface is better than expected, which is good because this is in practice a 6 X 4 stereo matrix mixer with an additional talkback mic channel and some other functions. Managing all this with some buttons and a single encoder could easily be a trainwreck!
Sound quality seems fine for the intended use, namely plugging in a couple of Volca boxes, a KP2 Mini, and a phone or whatever for sample playback. It has enough grunt on the headphone outputs to drive a pair of IEMs to any level desired.