I tried this last night for the first time (500ug buccaly) and overall it was a pretty unpleasant experience. I felt a deeply uncomfortable stimulation for most of the trip and that's about the extent of it, psychedelic effects were minimal (some rather dull CEV's) and other than some amusing conversations with my wife once the worst of the stimulation had abated I really have nothing good to say about the experience.
I find it interesting that the reported effects seem to vary from one person to the next, with enough LSD or DMT people seem to experience something roughly similar, with the NBOMes it's all over the place. A few posts up dan k states that 1mg of 25c is stronger that a hit of LSD, while I'm sure this is true for some people, I just can't see it, there's just no magic to these drugs as far as I am concerned.
Previously I have tried 25I and 25B-NBOMe which were pleasant, if a little dull and uninspiring. IMO, their 2c cousins are superior in just about every way. I don't understand how people can take such huge doses of these substances, 600ug of 25b was pleasant for the most part, but any more and I can see myself having difficulties.