So I already bought and installed a Garmin 520, but i'm still mulling over the option of repurposing a smartphone to use as a bike computer.

The phone in mind is a 4.5" Motorola E with GPS/GLONASS tracking and Bluetooth 4.0 (BTLE). Costs ~100$ new. Pair with HR Strap, high-quality mount (Quadlock), and BTLE Spd/Cad sensors, comes out to roughly same price.

Primary motivation are:
*Use Strava as primary platform, so why go through intermediate channel like Garmin software
*Direct integration of sensors
*More choices of monitoring apps
*Garmin known to be buggy, slow with fixes, etc
*REAL navigation, real usable screen
*No dependency on phone for connectivity
*Have all the Live Segments and etc built in (add cheap prepaid data SIM to phone)

Don't use Garmin Vector, so no need for Garmin's "analytics".
Not as long battery life, but unless its a 10 hour ride with screen constant on is a non-issue.
Not as weatherproof, but easily solved with simple cover, and not planning on riding in a thunderstorm either.

Only thing I see as a con is that going across multiple bikes, I'd like quick detachable non-magnetic Spd/Cad sensor that Garmin has...but thats only available with Ant+ (Although I dont really need CAD, just HR)
Also not entirely sure if BTLE supports multiple concurrent devices

Anything else I'm missing?