I started on a 2" wide strop, and it worked (still works) great, but since then I've graduated to a 3" strop and I definitely prefer not having to make an x-pattern. It's just easier and I feel like I can get into a nice rhythm faster with it. So if you can afford it, my advice would be to go with a 3".

On the flip side, you may cut it to shreds, and a 3" is typically more expensive. My first strop doesn't have a single nick on it, whereas my cousin's has some real nice "character marks."