I just use whatever laptop/tablet-type thing I have at the time.

My proper desk set up is just so much better than anything portable (not just keyboard, but also monitors, trackball, lighting, etc.) that it's not really worth doing any "real" work on the go - so while I have a number of portable devices, they're effectively just for doing stuff that can't reasonably wait until back at my desk.

(For that matter, I've effectively ditched all of my "work-capable" portable devices - my largest-screen portable devices are a Chromebook and a 13" cell-connected iPad w/ Magic Keyboard. They're both very capable devices in their own rights, but I'm not going to try to do <day job work> on them.)