While T-mobile may not have the best nationwide coverage, their customers are happy overall. The award was given because T-mobile answers customer’s calls promptly and resolves customer issues, often during the first call.
In my very slow quest for a mobile phone this is one more reason that my first look will be at T-Mobile. (The other reason is that their two phone plan is about $10 cheaper per month than the rest.) So in about 3 years you might be able to find me actually actively trying to get a mobile phone plan. (Hopefully sooner than that. ^_^)