[Moto Maxx General] ChazzMatt:
Ah, I had heard there was a "Samsung device" that would have LTE band 71 by end of the year, but when the Note 8 didn't have it I thought it was just a bogus rumor. So, it was the Samsung S8 Active.

The XT1254 is network unlocked. You can pop T-mobile or AT&T SIM card in -- it's just you would be limited to the HSPA/LTE bands the XT1254 has. For LTE, would be 2, 3, 4 7, 13. T-mobile uses bands 2 and 4. Where you would miss out is if band 12 is prevalent in your area, for T-mobile.

The XT1225 has 2, 3, 4, 5, 7, 17 -- which makes it about the perfect AT&T phone, but not quite as good for T-mobile... AT&T uses LTE bands 2, 4, 5, 17 -- with 5 being mostly a "filler" band in heavy congestion areas. I see it a lot in the northern metro area of Atlanta. If I didn't have it, I would probably be forced down to HSPA. (Yes, AT&T has also added a couple of other filler LTE bands, but they're more for the future.) In Atlanta area, 2/17 are the "workhorse" bands, then with LTE band 4 being more prevalent in rural areas of Georgia.

LTE band 17 is a subset of LTE band 12 and on all new AT&T phones they don't even list "17", instead they call it LTE band 12 now -- which has caused a lot of confusion for people who don't keep up with the cell phone industry. A lot of V30 users were complaining the US998 "open market" V30 doesn't even have AT&T band 17. I pointed out NEITHER DOES THE AT&T BRANDED V30! It's now LTE band "12". Seriously I've had this discussion half a dozen times and some people still don''t understand. "I just want LTE band 17." I keep telling them, do you not understand even AT&T isn't selling an AT&T phone that lists band "17"? I have to post screenshots of the AT&T website for the AT&T branded V30 H931. Do you see band 17 there? No. Do you see band 12? Yes.

It's because ever since January 2017 (a year ago), AT&T made their band 17 interoperable with T-mobile band 12, and since the frequencies of band 17 is actually a subset of LTE band 12, it's redundant to list both LTE band 17 and band 12. Sort of like listing a state instead of a separate city. "Florida" vs just "Miami". (Florida INCLUDES Miami. Miami is a subset of Florida.) New AT&T-branded phones from this year cover the entire "state" -- LTE band 12.

But point is, on the XT1225, it still is called LTE band 17 and I have doubts it would cover the LTE band 12 portions T-mobile uses. It would probably only cover the LTE band 17 portion (Miami) of the band 12 (Florida). However you would still be able to use HSPA where you didn't have LTE. So, flashing an XT1225 radio over the XT1254 was never really successful to my knowledge, as far as adding extra bands, but it really wouldn't help you with T-mobile anyways. The XT1225 does have more HSPA bands than the XT1254, but I don't know what HSPA bands T-mobile uses.

I've posted this before but posting it again to help others...

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Here's information about the Quark radios:

The XT1225 and XT1254/XT1250 all share LTE bands 2, 3, 4, 7.

The XT1225 additionally has LTE band 5 and 17.

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FCC ID IHDT56PK2

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The XT1254/XT1250 instead has LTE band 13 (Verizon LTE band), plus CDMA bands. While it does have some HSPA bands, there's not as many as in the XT1225.

FCC ID IHDT56PK1

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