well to be honest,
Emmet use a live drummer, and they can sound pretty Underworld-y sometimes.
But he's part of the band from the start, it just seems silly to stick a live drummer on a band that doesn't have a live drummer to begin with, just for live kicks.
I do believe Rick plays keyboard on the Nord Lead from time to time live btw. (I can remember some bootleg where he palys "riders on the storm" over Confusion the Waitress)