I use Pigma Microns for inking illustrations, but I much prefer a cheap Uniball Jetstream for writing and UI sketching. It's much smoother and just flows like no other pen I've used. Would never illustrate with it, since the ink isn't archival, but that's irrelevant for UI stuff.
It's funny you mention the Uniball -- I had some food delivered once, and the delivery man handed me a pen (in order to sign the receipt). I was blown away by the ink output and smoothness of this cheap-ass pen he gave me. It was, of course, a Uniball Jetstream :-P
I use Pigma Microns for inking illustrations, but I much prefer a cheap Uniball Jetstream for writing and UI sketching. It's much smoother and just flows like no other pen I've used. Would never illustrate with it, since the ink isn't archival, but that's irrelevant for UI stuff.