Which cell phone carrier for trucks tops, OTR?

I use both and have found that combination to work the best. My phone is dual SIM, so I have a Verizon plan and T-Mobile through Mint. There are some areas, like I-10 in far West Texas, where T-Mobile has much better coverage. Overall though, I find Verizon to have the stronger signal in most places, especially cities, as you mention.

 

Also T-Mobile had poor coverage in western states like WY, ND, SD and MT when off the interstates by more than 10 miles or so. I found that a pay as you go T-Mobile and a Verizon standard plan meant I had connectivity over almost all of the 48 and Canada.