I use two of them every night and have for the past couple of years. No problems at all except in extreme temperature changes, like going from freezing to warm, the extensions were very hard to get apart. I got some silicon spray and I wipe some on occasionally and that solved the problem.
I think if you use a Yamaha arranger, you will prefer using two of them because of the way Yamaha doesn't sum the stereo parts to mono very well.
DonM