I've bought a used 2003 XT last winter. Unfortunately, it's spent more time broken than running. I've had ongoing problems with the starter (both the motor and the starter clutch pins). It's dead right now... I have a new starter motor on order and the kickstart kit has already arrived, just waiting for a chance to install it.
When it was working, though, it's been a great bike. I usually see low-to-mid-60s mpg on the commute, more when dualsporting. I've taken it offroad a few times, and hung with bigger bikes just fine.
I've replaced the handlebars and installed a GPS 5 on them, with new grips, barkbusters and handguards. I have a spare set of wheels (one set for Distanzias, one set for knobs). I haven't jetted it, because it is primarily my around-town bike (I have a DRZ400 for the tough stuff) and I don't want to sacrifice the fuel economy. I've done the devilduckie
upgrade, too. Adds 5mph to the top end, dontcha know.