We did BBB at the MK over the springs solely because it was going to be a pain to get down the DS one to have it done and get back to the park. I didn't really want to take a 4 year old shopping with a $200+ dollar make over.
The BBB in MK was beautiful being in the castle and we really enjoyed it, and being right close to the princess meet and greet made it wonderful for her experience (all fast passes for the rest of the day were character meets)
(Also yes, there is a photographer that takes photos with the during and after portions of the make over, we didn't get any before shots though, I would have liked that)
The photos area in the MK park for BBB was not as good as the photos section I've seen with the DS BBB. The photo area seemed a bit cheap in MK where as the DS one had a giant Cinderella carriage (from what I've seen) that would take up the entirety of the photos background. Our photos had the edge of the screen in them and didn't quite come out as nice as I would have liked BUT the ability to easily get a multitude of princess photos after more than made up for it.