Pre-testing 5G internet speed...

I live a mile from a T-Mobile tower in an outer ring suburban area.   I get 500-600 Mbit down using my iPhone 12 Pro Max on 5G and 60-75 Mbit upload.

My T-Mobile Home Internet has been stable for the entire month I have had the service.   Device speed depends on the Wi-Fi level implemented on the device.   With a Wi-Fi 5 802.11ac laptop I get 200 Mbit down.  But with a Wi-Fi 6 802.11ax laptop I get 400-500 Mbit down.   Upload is 50-75 Mbit.  So upload speed is not symmetrical to download.  Both connect to the 5Ghz SSID.

I am not aware that a phone service is offered.

There was a heavy rain storm with high winds recently.  Service was not impacted.   I have not needed to restart the Gateway and I have not experienced any dropped connections; either the Gateway or Wi-Fi.  The Gateway seems to have a stable 5G connection as I have never noticed speed drops to LTE levels using my Wi-Fi 6 laptop.  

I was going to keep my Mediacom cable internet service active for a month while I evaluated the T-Mobile service.   I canceled Mediacom after just a week.

I can't say why others report so many issues.   I am very pleased.  My Gateway did arrive with the latest firmware loaded.

I agree that the Gateway device could use additional features that are available on most other routers.  I don't use a private VPN but the Pulse Secure VPN that I use for work does not have any issues with the T-Mobile service.

I connected my existing Orbi Router to the Gateway in Access Point mode.  I also have 2 Orbi satellites. I have a rather large home so I use the Orbi satellites for Wi-Fi in areas furthest from the Gateway. And I have an 8-port switch connected to the Orbi Router.  The switch did seem to degrade Wi-Fi speed when I had it connected directly to the T-Mobile Gateway instead.  I left Wi-Fi active in both the Orbi and the T-Mobile Gateway.   They seem to avoid collisions.  By checking the Wi-Fi properties of each they seem to have avoided using the same band for either 2.4 or 5 Ghz.

Results from the Speedtest App on my Windows 10 laptop with Wi-Fi 6 connection to the T-Mobile Gateway.   The test server used is a T-Mobile server 45 miles from my home.

For comparison, Speedtest from my iPhone with T-Mobile 5G connection: