The idle is a bit smoother, and suprisingly highway cruising is much, much smoother and doesn't feel as loaded. The milage has gone up a little bit too. I'm averaging 33 by the OBC, about 1mpg better than before. My wires were original, and in bad shape too.
Never heard of it!? There are a few people here running them, and one member selling kits.
http://www.318ti.org/forum/showthread.php?t=31333 I'd like to redo the wiring. It'd be nice if the guy sold the wiring seperate.