I sometimes like them and sometimes don't, and I think it mostly has to do with the rhythm of the reading. If they can be slipped in quickly, or actually *during* the speaking of line, so that it doesn't break up the rhythm, I like them. If it feels like there should be words next, pacing-wise, but a yawn or cough or whatever is inserted instead and delays the words, then I tend to slightly wish it hadn't been there.