I recently got myself a Lekato WS-70 UHF wireless kit after getting the bug (if you'll pardon the pun) at the NW bass bash in May. Used them at a few rehearsals and a couple of gigs and it's been great so far. Loved being able to do the walk out front and check the levels. Last outing I got a quick lesson in the perils of venturing out into the crowd - some guy wanted to put his arm around my shoulder and in his uncoordinated state he managed with bullseye accuracy hit my A tuner (yes, the A) and knock it out of tune. In a further showing of surprising accuracy, it was almost exactly a semitone out, so was able to finish the song by moving up a fret on the A string until the end. Live and learn!
But on a technical level, no complaints - I got no dropouts, no interference, battery is more than long lasting enough to handle a full gig (probably could chance two before absolutely needing to charge). I did suspect there was a bit of a negative effect on note sustain, but now I'm not so sure.