Like Av8 said, I'm a classic side effect queen when it comes to medications, and other than the suspected dry mouth from Clonazepam (and I have experienced
http://en.wikipedia.org/wiki/Paradoxical_reaction a couple times), it's been overall tolerable compared with the other stuff I've tried.
It definitely took care of my burning mouth that I had (which for the most part, thank goodness, is gone... yet still lingers a little now) unlike anything else, and for those that have burning mouth syndrome (which can actually be seen with MS due to brain stem lesions apparently), Clonazepam/Klonopin is the only medication that many will tell you has resulted in relief.
Before I quit smoking btw, I was taking ONLY .25mg in the evening, and .25mg at bedtime. I'm trying to ween myself back to this dose slowly now that my ATN/TN pain is starting to calm down, and the burning is not so bad.