I'm actually thinking about trying BE on my next trip to London, as some of the BE fares are as much as $210 RT cheaper than main cabin economy. I get a free checked bag with both my status and my AMEX, and I get AMEX lounge access in both JFK and LHR. I don't need to pay for frequent flyer benefits that I already get such as CLEAR, TSA Pre-check and Global Entry, and my status with the airline is now locked in. Also, the UK has gone to automated border gates, which has eliminated the need for Fast Track immigration as the long lines have gone away.