I refuse to be clean shaven, but I don't go around sporting something James Hetfield would be proud of either. I don't feel 'right' clean shaven, and everyone tells me I have a baby face - I look ridiculous without stubble, but with short stubble (hair clippers on their shortest setting) and a shaved, but not bald head, I get complimented more than I ever did clean shaven. I'm a broad, tall guy though so it suits me /shrug.
My ex-girlfriend said it looked nicer short, but it felt nicer at a medium length. She said she wouldn't want me clean shaven.
Age-wise, I'm 23 and get told I look 26/27 ish, but I tend to get on better with women a bit older than myself anyway so...
Edit: What I wear suits the stubble - jeans, shirts (proper button up ones) and black or brown leather shoes. Just because a few people have mentioned that it matters.
Also, some people in here have a very different idea of 'short stubble' to myself. My stubble is very much what people would call 5 o'clock shadow, and when it gets to what I think is medium, others would say short so... I should ideally post a picture, but I'm at work...