I was on live chess one night, and every match I accepted froze. It didn't affect my rating, but that's only because the server didn't assign me to the games. I rarely play livechess, so it was pretty disappointing that I couldn't play when the mood happened to strike me.
But I really find LiveChess to be useful for testing my understanding of openings. As long as I view it as a tool with limited impact, the bugginess doesn't bother me.