Im in the Miami area so the GPS isnt really that important since everywhere I ride its open...everything is non GPS other than to really track my rides in map format...

I like the idea of using my phone especially for casual rides with friends or family.

Plus the handlebar mount I can take calls and stuff too as Im riding a lot easier.The screen is HUGE too

Do the cadence sensors work with the apps???

I don't think a speed sensor is necessary???