The data usage shouldn't have too much of a difference compared to Android. You would still have email to auto sync, facebook, stuff like that. In Windows, its just about the same thing. Besides, if you would like to save your data usage, leave it off until theres a point where you NEED to use it. On Android, theres a data manager from the app store which does help me control how much i use. Sync all your data using apps at once to save data then shut off your data. Whats your data cap? If its >500, then you shouldnt have a problem with windows. If you REALLY need an app to keep track of your data, i can either go find one for you or make one for you. Try posting this on XDA-Developers forum.
Racquet : TGK238.1 2X / Head YTPP 1X
Strings : BHB7 17G 49lb / LUX 4g Rough 17G