I vote for width. I'm 6'3" and 310 lbs, which makes me one of those proverbial "big but not morbidly obese" guys (54 long). Still, I know people dread when they see me walk down the aisle ("how I hope he won't sit next to me...") much as I dread when *I* see a fellow big guy coming down the aisle...especially on an RJ (where having that fellow big guy end up next to me is not only likely, but inevitable!).

While I like the exit row for the extra leg room my 6'3" height requires, I've also stopped requesting them unless I have no other choice...because it's almost always 2 other fellow "big guys" in the row with me. That means multiple hours of banging shoulders and armrest contention.

There are much better odds of getting seated next to the small, nice-smelling woman in a non-exit.