I've just recently started growing my hair out after over a decade of having it shaved (not razor). I may not have looked great, but I saved a fortune on haircuts, shampoo and not to mention grooming time.
i cut my own hair so I don't know what the barber sizes mean.. actually I can see on my guide right now ha ha I use #1, 1/8", (3mm). I've done it since late in high school because my hair is wavy (its not straight and its not nappy, its a mixture of the two) and I never had a good hairstyle.. plus a shaved head is easy to maintain! lol.
i think it looks good for me... what I need to do is learn how to fade, then ill be set haha. but I'm afraid to try..
i'm rockin a #7 all around, but I think I might go a little lower on the sides, like 6, not too sharp of a contrast but a little shorter. I think it looks way better than my old hair, and way lower maintenance, so I don't think I'll go back. Incidentally a few years ago I was rocking like a 4 all around. My brother is in the army so he gets his hair cut with no guard at all.. hehe, guard... he's in the guard..