An update! Did my first ride today with the strava app. So easy and works like a champ!

http://www.strava.com/activities/95464380

I realize the calories is only estimated, as to cadence, I've a cateye on each bike and I keep my cadence in the 80 to 95 range for the most part.

Also, I checked data usage, and it looks like the 1.5 hr ride used 540mb for the strava app. So 2 gb will be plenty for me.