My DS had the Herbst. He wore just braces for about 6 months, then was in the Herbst for 6-9 months (while also in braces) -- and then finished out the last few months in just braces/rubberbands. The first two weeks in the Herbst were awful. Like the previous poster, he also developed deep ulcers/holes on the inside of his cheeks and was in a lot of pain. They prescribed some type of solution to heal the ulcers and also made sure he was using the wax properly and once he got over that hump, he didn't have any issues. I will say that he was glad to get it out, though -- it took longer to eat with it in, etc.