I also replied to the thread started by @
ginger50 and my reply is
here where I said that booking with a UK POS via AA's UK site was sometimes cheaper than via
www.aa.com but also that I was starting to do more nested flights where I'd book one US - UK return but everything between those dates would be UK - US - UK to benefit from cheaper fares and lower taxes.
I may start looking at flying with AC too if their flights really are that much cheaper, and so looking at cutting back on J travel and doing more in WT+ / PE where AA's P class fares can offer excellent value for money.