I've used Garmin Edge 705 and Edge 800 GPS devices on tour and century rides. They work especially well when you can plan your route ahead of time and then upload it to the Edge. Creating routes using only the device is much more frustrating. Entering destinations is cumbersome and the routes the Edge chooses aren't always the most bike-friendly. I get anywhere from 12-16 hours of life on one charge; the Edge 800 seems to be a bit better than the 705 in that respect. I find the displays on the Edge 705 and 800 are generally more readable in direct sunlight than any of the smartphones and tablets I've tried (Nexus 5, Nexus 7, iPhone 5, iPad mini with Retina display, 1st generation Kindle Fire, etc). The Edge works so well, I can't remember the last time I needed to look at a paper map...