i only make them small with a light pencil on essays. and i didn’t put any on my sat essay, i think. but definitely in texts and emails–they’re very handy when you want to point out that something is funny, or that you just made a joke, and you don’t trust the reader to come to that conclusion on his own.
that said, i agree they are not very polished looking, but at least they are cheerful looking. there aren’t enough smileys in the world today
🙂