This looks like a pretty cool building, but the lighting isn't very good. Shooting when the sun is lower in the sky would highlight one side of the building and put the other side in shade, which would emphasize the shape of the structure. It would be worth shooting this one again at a different time of day.
I remember when you could get a decent landscape shot from the nearby hill that would show the mission alone in the middle of the desert, and it truly stood out. Interesting that there's almost always a time when the mission was in the middle of repainting. There are many, many cloudless days in Tucson, but the sky has never been that color of blue. I suggest you've over-saturated your image.
Ow...processing is a bit much. There are strange artifacts, haloing and oversaturation as a result. Its a beautiful building but your processing takes away from it. Also use the full size allowed, you have 800 px (on the longest edge) to work with.