I've got a Edge 305 bike 'puter, however I want something to provide some navigation.

I'm trying to decide between the Nuvi 550 and the eTrex Vista Hcx. The two things I'm after are preloading routes from bikely, mapmyride etc, and a good base map where I can start somewhere and meander around the country highways without spending an hour planning a route to get back to the truck. Won't be doing any off road riding, so that's not a issue.

The 550 is waterproof and has a 8 hour battery, plus it's replaceable - so you can carry a spare.

Any opinions?

marc