I have some cages with the single swing door and in some respects, I like them better than the dual sliding. They allow you to open the entire cage, which makes manipulating the animal and cage contents easier (and more convenient). Cleaning will undoubtedly be easier. Dual doors really only helps with feeding if you have a particularly aggressive feeder. In my opinion, ball pythons don't really fit this category.
My issue with acrylic single doors is that when they are fairly large (> 2 ft or so), they seem to warp over the course of several years. It isn't generally horrible, but if you have something thinner like a colubrid, it can be problematic. It is less of an issue with thicker boid snakes.
I don't know if this is changeable, but I would highly encourage you to switch your GTP cage from an A10 to something like a T5 (3' x 2' x 2'). I think you'll find that the length in more useful than the height.