im directly on ATT with EPP discount with old 2GB and 200 msg (I dont need unlimited texting), 450 minutes with 2000+ rollover left each month. All I pay for smartphone is $70 - $5 for u-verse bundle discount.
I recently upgraded my smartphone to iphone 5 and was able to keep all my plans. I paid $36 upgrade fee but got my phone from Apple store since all att retail stores and most Apple store are out of stock. LTE performs much better than 3G. The phone is very fast.