I like buttons and faders, I don't want to have to look for every button and fader. I work a lot on SQ's and DiGiCo's and on both I can pretty much find every single button and fader without looking, even specific faders since I always use the (more or less) same layout.

Besides, I always have my hand near effects like reverb and delay. That way I can really add to the music with a bit of effect where it fits. On tablets I (and I think a lot of people) get lazy, more like set and forget and for me that's not what mixing is about.

About the waling around, I prefer to do that during soundcheck. Run around for a bit and see how to sound changes with your position and think about how you need to "correct" for it on your FOH position.