Last year when I went to CDMX my T-Mobile phone roamed on Movistar and it seemed to work well. I also had a Telcel SIM for my MiFi and that too worked fine. You'll want to make sure your device can use the LTE bands most common in North America (2 and 4 at minimum, I forget what other ones the Mexican carriers use).
Of course, YMMV, especially in more rural areas.