When I went through this, the feedback was about 70-30 in favour of the 20″ model over the 25″ model.
I went with the 25″ (XL) model on my Lund Pro V. The price was right and I didn’t want it to be too short when conditions got rough – which is when you really need it.
It works great, but it does drag in the water slightly at “plowing” speeds. Nothing serious, but you do have to be aware of it.
I think if I was to do it again, I’d look a little longer for a good deal on a 20″ model.
Waxy