Full-tunneled through Mullvad via Tailscale and on a T-Mobile hotspot. Not unhappy at all with these speeds:
❯ nix run nixpkgs#iperf3 -- -c Connecting to host , port 5201 [ 7] local port 64498 connected to port 5201 [ ID] Interval Transfer Bitrate [ 7] 0.00-1.00 sec 3.50 MBytes 29.3 Mbits/sec [ 7] 1.00-2.00 sec 3.25 MBytes 27.2 Mbits/sec [ 7] 2.00-3.00 sec 1.12 MBytes 9.44 Mbits/sec [ 7] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec [ 7] 4.00-5.00 sec 256 KBytes 2.10 Mbits/sec [ 7] 5.00-6.00 sec 896 KBytes 7.33 Mbits/sec [ 7] 6.00-7.00 sec 1.50 MBytes 12.6 Mbits/sec [ 7] 7.00-8.00 sec 1.50 MBytes 12.6 Mbits/sec [ 7] 8.00-9.00 sec 1.25 MBytes 10.5 Mbits/sec [ 7] 9.00-10.00 sec 1.38 MBytes 11.5 Mbits/sec - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate [ 7] 0.00-10.00 sec 14.6 MBytes 12.3 Mbits/sec sender [ 7] 0.00-10.18 sec 14.4 MBytes 11.9 Mbits/sec receiver