All GPS watches will have a USB connection, because that's how their batteries are charged. I'm pretty sure they can all be used for data transfer and not just for juice.
Are you going to wear the watch on your wrist or mount it on the handlebars?
I don't know anything about the M5. The only Suunto I've ever used was the Core, their altimeter watch. It did nothing you wanted, but it was very good at everything it did, and very useful on the trail. I know their Ambit series is pretty well respected. It's also too complicated for my taste - do you want the sport model, the peak, or what? Their new Spartan Ultra looks interesting but at this point it's a very expensive beta product with few real features.