For me, the convenience of Uber was always in the predictability of when the car would arrive. Flywheel (http://www.flywheel.com/) has finally effectively solved that problem for regular cabs, after half a dozen apps tried. Anecdotal conversations with taxi drivers indicate that they are pretty happy with the Flywheel service as well - it is definitely the best received app by drivers.

Using an app that seems to treat driver's more fairly is worth something to me, YMMV.