I just picked up a new board and switched from a 159 Regular to a 159 Wide. I also switched from a size 10.5 Burton Ion (smaller footprint) to a 11 Nike LunarEndor boot, so I think it was the right move going to a wide as my 10.5 boot was already cutting it close.
Weight also makes a difference. I went up in weight from 200 to 220 and could feel the difference in flex and control on my regular board. It's a minor difference, think just a cm ... could be wrong.