[Rogue5]

They rock. I can get on a plane from to anywhere in North America (or europe if you buy the add on maps), jump in my rental car and within seconds know exactly how to get to my hotel or other destination. often for work my boss will simply email me the address of a building I'll have to go survey it would be annoying to have to print out dozens of google maps per day, plus the gps will reroute you if you miss a turn.

I have the Nuvi 350, it's been awesome, but I don't see it having an advantage over the C340, unless you want to use it outside of the car (it's smaller and has pedestrian mode), and I've done this before. Also if you find yourself needing your current coordinates you can get them from the Nuvi, and not from the c340 (or so a coworker tells me)

I don't have any experience with the phone-based gps setups.