If your decision to buy Samsung's Galaxy S III (S3) on T-Mobile comes down to the LTE radio within, prepare yourself for disappointment.
A T-Mobile spokesperson confirmed to CNET today that despite the same LTE radio in every GS3 model coming to the U.S., Samsung's new flagship Android 4.0 phone will not ride T-Mobile's forthcoming LTE network:
The Samsung Galaxy SIII won't run on T-Mobile's LTE network in the future, but we will continue to operate our HSPA+ 42 network when we launch LTE in 2013.
T-Mobile's AWS spectrum is the culprit here, since it will carry T-Mo's LTE network. AT&T and Verizon, on the other hand, use bands in the 700MHz spectrum for their LTE. Adding support for T-Mobile's unlaunched LTE network would mean adding more bands in the LTE radio.
"The device is the same across carriers," a Samsung spokesperson confirmed in an e-mail, "but [the phones] are optimized to work on each carrier's specific network."
However, a T-Mobile spokesperson updated his statement to contradict Samsung: "Galaxy S III contains a different chipset than our competitors. Ours is the MSM8260 which does not support LTE, only HSPA."
While LTE promises greater speeds, potential buyers shouldn't underestimate T-Mobile's HSPA+ 42, which independent tester RootMetrics found is.
In my own tests on the Galaxy S3 in the San Francisco Bay Area, T-Mobile's data speeds peak at about 16.5Mbps. While AT&T's download and upload speeds were faster on an absolute basis (up to 33Mbps downlink,) I also stumbled into plenty of dead zones.
If you're deciding between the two GSM carriers, price could be another consideration. T-Mobile's 16GB Galaxy S3 costs $279.99 with a 2-year agreement or $229.99 (Value plan, you pay interest) and $50 more for the 32GB capacity. AT&T sells the Galaxy S3 for $30-to-$80 less at $199.99 for the 16GB version. AT&T doesn't sell the 32GB capacity. Of course, the monthly data plan also factors into your total price for the phone.
Updated Tuesday, June 26, 2012 at 1:25pm PT with new information from T-Mobile about the components.