Genius is occasionally cool (for example, when I tried it with a New Bomb Turks song I got a mix that included Redd Kross, Richard Hell, Van Halen, and Rage Against The Machine), but for me the whole point of shuffles and mixes is variety - most of the time it just spits up 25 songs from the same general category (for example, every time I try it with GBV I get a totally predictable list of Pavement, Sonic Youth, and YLT songs - all stuff I like, but no real variety).
Right now, I'm in Milwaukee, listening to the most recent archive of WFMU's Night People and wondering whether to go wander around by myself. Totep and that other fella, PM me quick if you're around!