Well, I dunno. That many mg of clonazepam makes me feel pretty nice - but over 6mg or too much alcohol (more than 3 beers or so) and you find yourself acting retarded and blacking out.
Even with no tolerance I'll usually start out with 4mg clonazepam, so maybe if you're tolerant you might have to take a bit more, but really you're probably not gonna hit some massive "sweet spot" if 4mg doesn't do shit for you, and the blackout doses can be pretty subtle themselves. You might not be feeling it all night until you wake up in a holding cell.