Beware of new phone / upgrade and software updates.
Just upgraded two lines with samsung sgh-i337. One phone had version 4.3 android, the other 4.2.2
We left the ATT store and by the time we got home we had exceeded our data plan with the phones updating the software via mobile network.
Our original data plan was 300mb having used only 60mb a month in the past.
I could be descriptive about how I feel, but I'll leave it at I'm not real happy.