I do it all the time. Total travel time is longer than the traditional kangaroo route via the Far East/Middle East by about 6h – 8h across the Atlantic, 4h across continental USA and 14h across the Pacific (or 10h LHR/LAX and 14h across the Pacific but this option includes a longer layover in LAX). All up, including transit of 30h. Fares in Economy range from £950 to £1,300, depending on departure points. I found ex-DUB to be very competitive. Fares on the traditional routes are lower but you earn significantly more miles/avios this way.