On QM2, Premium Package; I tried running Speedtest.net on a 'Motorola Moto G 5G Plus' several times. The test failed to run each time.
However in 14 days 890 photos and 7 videos totalling about 5GB backed up to my OneDrive folders without any problems. I compressed photos being posted to CC, Facebook and WhatsApp to make upload times faster.
Signal in cabin wasn't great, but I had no problems in public areas accessing websites, email and banking apps.
The system did log you out due to inactivity or loss of signal moving around ship. This wasn't a problem if you understood the stages required to re-connect, taking 10 to 15 seconds each time.