I suggest a bicycling specific backpack. I've noticed that after having to commute with a mess bag, my spine has paid the price for it. It wasn't as big of a deal when I was in school, but the last 2 years as an everyday commuter have really taken their toll on my back. Most of the major mess bag companies also make a backpack option as well.

As for Chrome bags, I think they're great. Overexposed, maybe. But top-notch quality.