I'm a road cyclist. I rode a few different pairs of Oaks before I landed on these.
The main point of difference on the XLs is the height of the lens. These are tall enough that when you're in the drops, the top of the frames don't block your field of vision. This was not true of the standard Radarlock lenses.
After riding a few months with the photochromic lenses, I had to pick up a set of darker lenses. The photochromic ones don't get dark enough for my taste. Still, these sunglasses are amazing.