Not so great. I mouth off. More'n usual, anyway. Go colder apeshit than I normally would on whoever the target for the day is, knock back a few drinks, maybe completely lose my temper if it's somethin' that's really managed to get to me... I'm not exactly gonna keep quiet; unless it's somethin' real serious (in which case I think it'd be called something other'n just a "disappointment"), whoever's around's gonna hear about it.
Pretty much, I bitch like nobody's business.
Then again, s'not really like I get disappointed that often. You'd need a bit more faith in the idea that things're gonna turn out okay than I've got.