tdt009wrote a review of Oakley Radarlock XL Straight Sunglasses on October 27, 2013
Familiarity: I've put it through the wringer
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.
I also rode a few months with the Radarlock XL photochromic lenses. I found that they didn't get dark enough for my taste in bright sunlight.