zkSharks
Retired Moderator
The reason that site isn't 100% accurate is that it's user input driven. Only people who know about the site and are using non-AWS phones on T-Mo may report their results.
That allows for the absence of reports, yes, but does not correlate with incorrect reports per se. T-Mobile's 1900MHz refarming is rare, and will likely not take place in many markets. Don't expect to see a very large number of reports on there; it's merely an indicator of the regions in which T-Mobile has begun this refarming in order to re-allocate spectrum for future LTE and HSPA+ 42 establishments.