A good thing? Trying to seem very genuine in a story-telling-like way...
OR a bad thing. Too informal?
A bad thing- telling stories is what you do around the campfire with your friends after a long night of tripping on mushrooms and smoking chronic. A personal statement is an attempt to supplement/compensate for any potential inadequacies in your application. As such it must be an artful permutation of relatively formal writing with a subtextual window into your own unique qualities/experiences.
Trust me on this one- I go to Cooley.