That sounds familiar... when my husband and I were first getting into snakes we considered the same two. They are both very easy to keep, but the temps and humidity are slightly different for each. It basically depends on the personality you want in your pet. Corns tend to be constantly on the go when you're holding them, like they have somewhere to go and they're already late. Balls can be more content to sit still and hang out with you. Of course those are broad generalizations, and there can be exceptions!