Yes - 2 1/2" is my standard too, but if I'm making something that won't get 'wear and tear' like a wall hanging, I usually cut 1 1/2" so don't fold.
I've never done wider. I'd be too apprehensive about getting the measurements right when sewing on the binding so the quilt sandwich fills it.
Would love to see a pic of it when done and how far in you had to stitch the binding on.