That was my real concern. That and USB charging. I prefer the Exposure's for their nice big batteries that I can charge normally or in the worst case scenario pop into a shop for.
I only use mine for racing so it's fine, but I think I'd get annoyed with the battery life if I was commuting with it. Surprised you'd find USB charging a problem, you must have a USB wall adaptor?
I haven't found that at all. Battery life is a little poor though.