Emob78: Especially when you look like I did, which was Bilbo Baggins the nasty hobo who hadn't bathed in 4 months.
I had the same problem. I am lazy going to barber, I think the last time was over 4 months ago, and hair started accumulating.
So either I had to go to barber (the one nearby charges a freaking 34€ or so for a simple men haircut), or do this. My hair doesn't grow neatly longer, but it basically grows to all directions, almost like an afro even though I don't have curly hair.
Plus, at least I got some use for that second-hand headshaver I bought from a flea market last weekend. This is not exactly the first time for me, I did shave my head to a 3mm when I was in the army but that was eons ago.