SEA-TPE a couple of weeks ago then TPE-SEA last week. Wifi speed and connection stability were poor. It was much better when wifi was chargeable unless you got a code prior to the flight (C provides it, don't know about other classes).

Don't know if free wifi plays into the decision of their money making customer segments but if I needed wifi inflight, I would not choose BR based on this experience. All else being equal, this change is a negative for me when flying C and probably net zero if I was in Y (since it's basically unusable)