RE: John80: "At this point the difference in functionality between the stand alone GPS units are the smartphone competitors are not significant anymore.
+1, I use Wahoo fitness app and Duotrap sensor calculating wheel distance while some of my friends are using high end garmin, and others MapmyRide GPS.. 30 mile rides compare at +/- .1 mile, negligible. Screen display in sun is another nonfactor. First, I rarely have a problem seeing the display when I look at it.. which is not very often because the Wahoo app is calling out full ride averages (Cadence, distance ,mph, etc ) on the 1/2 mile and segment averages on 5 minute intervals .. so there's no reason to be watching the screen except for the occasional look. Battery usage varies by phone. Two hour rides with my Lg3 uses approx 25% with music on and wahoo display working at all times. I have not compared elevation gains, etc with somebody that has altimeter, but, I've read Strava elevation gain calculations are fairly accurate.

My advice is to try a few smartphone apps before buying a dedicated computer.