My wi-fi is Verizon and my cell is T-mobile. Many times I do not have a signal with T-mobile, and hook up the computer, and no problem. Lately I have been seeing many times where my T-mobile is saying calls forwarded or emergency calls only. Now just waiting for the contract to expire, then add a line to the wife's Verizon.
Have you seen the new T-Mobil ad, it has a lady on a motorcycle running what looks like maybe I-70 from the east to the west coast and they are supposed to have over 50,000 cell towers.
I switched from TMobile to Verizon about 2 years ago. Can't compare the too. TMobiles Coverage is a joke in some places.