I'm old fashioned I suppose, is use a good old Garmin 1450 with a universal ram mount on the brake reservoir.
When trying to decide on a GPS solution, I thought of three determining factors. One, a dedicated gps will not be interrupted by phone calls, texts, etc. two, the screen is very glove friendly. And most important, when it kicks off the bike for whatever reason (accident, bump, pothole, etc.), which would I rather lose, an $800 iPhone with all my contacts and info, or a $50, easily replaceable Garmin?
And I have had one kick off the bike. Good decision.