I say, pick the one you are most comfortable with, it will the be the one you will get the best images with.
Some people may say choose the one that would be more rugged, and be easiest and quickest to repair, so incase something does go wrong, you can be back in action quickly.
Some may say to choose the least flashiest, expensive cameras are a target in many countries. You cant take any photos if you dont have a camera, or worse injured if mugged.
Or just bring both, its good to have a backup.