I like Jamie. I know a couple of Jamies my age (early 40s) and a few DS1s age (mid teens). I always prefer the proper name on the BC - there's choice for them then. My James is Jim. He's the only one I know and it's lovely.
I don't like it. It sounds 'wet' to me, like Tim. Aside from that, I'm a fan of grown-up names on birth certificates. There was a point, aged 11 or 12, that the vast majority of children in my class with cutesy short-forms asked to be called by the more grown-up version. 3 Jamies became James, the Dannys became Daniel or Dan and Nicky became Nick. Not one of them has gone back to the childhood version.