I'm a diehard Squeezebox/LMS user still using three Squeezebox devices on a daily basis.

With that said, the synchronized playback has never been really what I would call great. It is roughly in synch so you can go form room to room and hear the same stuff, but when you get to an area where you can hear two devices at once there is definitely a disconcerting delay on one of them. Maybe that's because I've got one hard wired and one on wifi, but I thought it was supposed to correct for these differences.