I own both a Nuvi and a Garmin gps. Avoid the Nuvi for bicycling, the battery life is way too short and it's not designed to all the bumps of bicyling. The Nuvi is also not water resistant at all.

I would recommend the Dakota 10 hiker/biker bundle, goes for around 200 bucks online. It includes the map CD to load maps and a bicycle mount for your GPS. The Dakota 10 will also give far more data. And it is a touch screen.

The Vista HCx is a great unit for bicycling also, in fact it's a great unit. The only downside is that you will either have to buy the mapping or use a 3rd party website like gpsfiledepot.com

But you won't go wrong with a Dakota or Vista/Legend HCx