Sorry, What I meant is will it get by the system sweeps. As in, can you use it on the dumbphone plans without getting the dread "we added the appropriate data plan......." text message. Both versions will definitely work on with ATT's HSPA (3G) and the RM-893 (T-Mobile version) should work get LTE on ATT's network (with the appropriate data plan) although I don't think anyone has confirmed this as of yet.
If AT&T finds out, they will add the smartphone data plan automatically. From their
legal terms:
"
6.3 What Are The Voice And Data Plan Requirements?
A voice plan is required on all voice-capable Devices, unless specifically noted otherwise in the terms governing your plan.
An eligible tiered pricing data plan is required for certain Devices, including iPhones and other designated Smartphones. Eligible voice and tiered pricing data plans cover voice and data usage in the U.S. and do not cover International voice and data usage and charges.
If it is determined that you are using a voice-capable Device without a voice plan, or that you are using an iPhone or designated Smartphone without an eligible voice and tiered data plan, AT&T reserves the right to switch you to the required plan or plans and bill you the appropriate monthly fees. In the case of the tiered data plan, you will be placed on the data plan which provides you with the greatest monthly data usage allowance. If you determine that you do not require that much data usage in a month, you may request a lower data tier at a lower monthly recurring fee."