I have purchased a Garmin Edge Touring, a little more than a year ago. Didn't like it for several reasons. Some, listed in random order, are (1) poor battery life. Even during a single day outing you should carry a battery pack. (2) buggy. The unit would crash during a ride. Or wouldn't ba able to calculate a route. (3) lousy display. Difficult to read in bright light, difficult to navigate, small. (4) cumbersome. Planning a route on-the-fly is an exercise in patience. The process involved a computer, Strava and connecting the Edge with a USB cable, (5) affordable units such as the Edge do not support ANT+.

So I now use a dual system: a Bontrager Node 1.1 ANT+ computer head, that is very much like the Sigma .12 family. Small, battery life measured in months, and reliably provides feedback on key metrics (speed, distance, cadence, HR). My principal motive was to have a measure of total distance. I nearly always ride with this unit turned on. Inexpensive and works very well.

When I want real-time navigation/routing, I generally run Locus Pro, and sometimes Google Maps on a Samsung S5. Much much much better all-around experience. Creating/updating a route on-the-fly is easy, even when you are offline (with the addition of bRouter). The only drawback is that when it rains, drops are often confused with a touch -- the display is unusable at best, and will trigger all kinds of strange behaviors at worst. Locus has a feature that disables the touch screen (requiring a key-press to resume standard behavior).

My setup includes an in-steerer USB charger (forumSlader) such that power is not an issue, and a dedicated handlebar mount, where the clip grabs a protective shell. As fate had it, I was given another S5 by someone upgrading to a newer smartphone, such that I have one dedicated unit (with extensive maps and touring oriented screen configuration.

I would argue that this system beats Garmin's offering hands down, with two caveats -- Garmin units are preferable if you want to upload ride data. They are also better designed to withstand the rigor of weather (and cycling in general)