Here on the outskirts of Atlanta, Sprint and T-Mobile have more or less equal coverage, with one picking up where the other doesn't most of the time. The issue with T-Mobile is that it's more difficult to get a signal indoors, depending on the building material.
For example, at my job we're in a large warehouse with metal walls and framing, lots of pipes, and suspended ceilings. That makes the building difficult but not impossible for radio waves to penetrate. All four major carriers saturate the area; stepping outside you get full service on all of them. But of the four, only T-Mobile has zero coverage once you step inside the building. The rest are usable to varying degrees, with AT&T and Verizon the two best, and Sprint is decent inside.
And just so this isn't purely anecdotal, T-Mobile has acknowledged issues with using their service indoors:
> On the other hand, have you looked at getting a femto cell for your warehouse (or using a service like Google Voice to get wifi calling)?
I'm the only employee using a T-Mobile compatible phone so it wouldn't be worth doing. We've put WLAN access points throughout the warehouse (one of my first projects when I went full time there) so it's saturated with Wi-Fi. I can't use Google Voice or Hangouts for receiving calls, since I mainly use a Windows phone, but I do have that set up on my Nexus and it works well there.
Basically, 99% of what I use my cellphone for at work is covered by Wi-Fi, and if anyone needs to reach me they can just call the company.
For example, at my job we're in a large warehouse with metal walls and framing, lots of pipes, and suspended ceilings. That makes the building difficult but not impossible for radio waves to penetrate. All four major carriers saturate the area; stepping outside you get full service on all of them. But of the four, only T-Mobile has zero coverage once you step inside the building. The rest are usable to varying degrees, with AT&T and Verizon the two best, and Sprint is decent inside.
And just so this isn't purely anecdotal, T-Mobile has acknowledged issues with using their service indoors:
http://arstechnica.com/information-technology/2014/10/t-mobi...