T-Mobile 5G Home Internet & TP-Link Deco Mesh WiFi System (Deco S4)

T-Mobile does have the trial period. If there is good coverage in your location and it is not too congested for traffic on the cells it might be good. It is hard to be sure as every location is different. Some gateways are better than others. I would not give up what I have as a known entity until I have given the solution a trial. The TP link solution should connect via an Ethernet cable to the gateway but without testing it one cannot say it will work. It might or might not work well. Testing would be the only way to be sure. You might get the T-Mobile gateway in house and then find you don't like that part or the bandwidth delivery is not what you expected. Maybe you have neighbors that have T-Mobile service. I would try to find out about the experience others in the area have had.