As noted above it all depends what you want out of the equation.

For 150k you can get First Class to London but you'll get hammered with taxes and fuel fees (roughly the cost of buying an economy ticket).

You can trim this by $200 or so by starting your return from somewhere like Paris and just transiting London on the way back, as you can avoid the UK taxes but you'll have to pay more miles (another 9k)

So if you're going to detest the surcharges and usually go to - say - Hawaii anyway, you might be better off ditching the companion pass and simply using the miles as a low cost way to fly AA on domestic flights (very low taxes...)