I used to ride with heel over hang but my toes within the edge of my board (toe under hang I guess) before I bought new bindings - it was due to the fact I have small feet and I preferred a more customized width in my stance than having feet dead center on the board.
Since switching to my new bindings where I can do both, I haven't noticed any difference.
On another note, I've also ridden 168wide boards where I haven't had much trouble - and I definitely had no overhang on either side of that board. It's obviously slower, but wasn't a huge problem. It might pay to explain your stats like boot size, height, weight and the board you're wondering this about for.
Last edited by nzshred; 08-02-2012 at 04:08 AM.