It's interesting to me because people always say this is a huge issue with T-Mobile. I've been with them for a decade now, and have had very little coverage problems. I've been across a lot of the country and the two places I can actively remember where I got zero coverage was in northern Minnesota and Death Valley.
Their data does get a little flaky the when out of fairly populated areas, but I have seen this improving very quickly and can make many long drives with full data coverage.
>the two places I can actively remember where I got zero coverage was in northern Minnesota
I took the Empire Builder recently, which basically skitters along the Northern border from Chicago to Seattle/Portland, and T-Mo coverage was nil for the bulk of the trip. Can't say I really minded, though.
Could be different phones and the bands they support, in part. My brother and I are both on T-Mobile, but he gets better data coverage in the U.S. (we both get perfectly fine voice coverage). I have the "Global" version Moto G, which doesn't support either of: 1) any of the 4g/LTE bands, or 2) the 1700 MHz AWS band on which a lot of T-Mobile's 3g coverage is located. (The U.S.-version Moto G does support 1700, but then isn't usable for 3g in Europe, because it lacks 900/2100.) Whereas he has a Nexus 5, which supports LTE, giving him 4g coverage in some areas where my phone falls back to either EDGE, or no data at all.
I have their pre-paid plan, which apparently doesn't get me the "Service Partner" coverage, so there's a large band on the flyovers that I have zero reception in.
You're correct though, around my city and most cities I've been too domestically, I've found the coverage to be pretty good. Either way, the cost and ease have kept me on their program even with the occasional coverage gaps. But somebody routinely out for non-metro trips might not like it.
It's been my experience that there's not much difference between AT&T and T-Mobile overall. Which one is better just depends on where you spend most of your time. People with Verizon seem to get a signal virtually everywhere.
On the I-5 pacific corridor during our drive last summer from CA->WA and back, I got bupkis coverage for TMobile data in most of northern california and oregon (and call coverage was spotty). However, our Verizon 4G iPad also had weak/no coverage in may of the same places.
However, I would never go back to ATT/VZ absent a major change in their behavior. Happy TMO customer.
Have a look at http://opensignal.com/ - the map is built by data submitted from their app on phones. Unfortunately they do not show areas where the phone reports no signal.
In my area (Santa Cruz, CA) tmo are weak. Heck I barely get coverage in my house, and walking along West Cliff drive has sections with no coverage. Verizon is strong.
However I very rarely actually use the phone as a phone so I mostly don't care.
I think you're both right. I have been a T-Mobile customer for 10+ years. I have probably better coverage while in a city, like Boston, than anyone I know.
I also have some pretty bad coverage when I go up to Vermont.
So, if you stay in the cities. Excellent Coverage.
Roam into the rural world: Spotty coverage.
Fact, though, even AT&T's coverage in some of these same locations is pretty poor. Verizon seems to work best.
Re: Vermont -> I had no T-Mo coverage at all in southern Vermont, specifically Brattleboro, which is in the extreme southern part of the state and not far from civilization. Out here in eastern Washington I've had pretty good coverage (though I AM on the I90 corridor - civilization again, relatively speaking) and am a happy camper on their $30/mo, 100min, 5G Walmart plan.
