I did some math. I have booked a trip DUB-LHR-BOS-PHX-LAS / SFO-PHX-JFK-LHR-MAD additionally BSL-LHR-DUB / LAX-PHX-SFO / MAD-LHR-BSL. With BA old system I would get 960 TP. With AY i would get around 29'000 TP. This costs me £~2.2k. To get OWE i would say you would need £5k to £7k. The issue is you would receive more TP on flights towards US than Asia. Flights to Asia are mostly 100% to 125% per Mile in I fare class.