Garmin for double century?
Hey all. I've been thinking about getting a Garmin, or some other GPS computer, but I'm concerned about battery life. I ride double centuries now and then, so I need something that I can be confidant will last 15-17 hours on a single charge (yeah, I'm slow). The unit I keep considering is the Edge Touring (I like the altimeter option and don't need the bells and whistles of the 810), but Garmin indicates it and other devices will last "up to 17 hours." Seems like a red flag to me, since I find specs usually err on the most optimistic/unrealistic side.
I've seen people using GPS's on doubles before, but what are they using? Or are they just faster than me? :)
Anybody have any thoughts or suggestions? Otherwise, I'll just stick with my little ol' CatEye.