Either the carbine mount on my alto sax (TAS-150) is too high or my neck is too long, I just can't get into a comfortable posture with this thing.
Build quality is fine, although the carbine is plastic it doesn't feel flimsy, strong tension in the spring. Super easy to adjust, the padding on the neck is nice too, but I need to tighten this thing almost all the way to get the mouthpiece level so the strap starts to feel constricting.
Neck strap is really something you have to try before you buy, or order a few and return those that didn't cut it.