We want to install cellular modems in our elevator machine rooms for emergency communication (when you press the emergency button a service answers via voice and the service gets a video of the elevator interior). I used Oookla Speedtest app (which can use a couple hundred MB for testing so the below tests took a good chunk of my monthly quota).

Machine room 1 (near the front door): 80 Mbps down, 4.4 Mbps up, 100 ms ping.
Machine room 2 (near garage entrance): 200 Mbps down, 0.1 Mbps up, 80 ms ping, 90% packet loss.

Machine room 2 has bad upload. I tried two more tests:

Machine room 2 (outside door): 565 Mbps down, 14.7 Mbps up, 55 ms ping.
Machine room 2 (inside, near vent): 13 Mbps down, 1.7 Mbps up, 192 ms ping, 87% packet loss.

I'm guessing the installers will test the service to make sure bandwidth is adequate. In both machine rooms I get 2 bars so should be fine.

Also I use Mint which I heard is deprioritized on T-Mobile network. But I ran my tests at 0200 so network had low usage.