For Edge specifically:
+ Small and light
+ Features speedometer, altitude (!) And basic navigation
+ Battery will last at least a Day - more than 10 hours, I do not drive but..
+ Robust, has also survived several downpours
+ Mounting with rubber on any handlebars
+ Loading feature via any USB charger.
+ Interface GPSies works beautifully (see above)
+ Recording and storing driven tours
+ Good display of tracks and the travel progress (km / time to destination)
+ In route deviation deviation alarm Directional back to Route. It also appears a minimap. With increasing deviation, the scale automatically changes.
Easy to read in daylight +, emergency lighting at night by keystroke.
+ Use it on each wheel as a bike computer. No cables, no settings.
+ Place the satellite's relatively fast, especially if you "continue" the tour.
(+) Takes a little longer if you start at a new location. This is art, not a minus!
- Nothing when you look at the price-performance ratio. I bought it for 120 about a year ago - now there are the thing for less than 100 and replaces it alone is a bike computer with altimeter.
For day trips:
Morgends plan, download and possibly insert expression or map. Nothing more needed.
Optional safety may still plugging a smartphone.
My long-distance and travel system:
Planning small MacBook Air for daily and Download -.
- About Hotspot smartphone of computers is necessary at any time online. You can use it to reschedule, search hotel or restaurant, ... whatever.
- With USB charging plug for Sigma Lithium Ion battery (light) can be computer, Navi and telephone invite also necessary if you take does not have a hotel.
My advice: stay away from the expensive Navis with frills; it would rather invest in a neat little machine. He can always more and in total costs "my" system not much more. Works with Microsoft, Linux and Apple OS. Experiments with an Android Tablet, GPSies and couple Garmin Edge I gave up in frustration, it should indeed go - but I do not attempt it.
Conclusion: The Edge meets the basic functions on the bike perfectly - the planning is going well at the computer.