I find that it depends greatly on potential future reward trips and class of service. For example, BAEC currently offers some lovely business class reward opportunities on partner airlines other than BA, for which it typically also does not charge fuel surcharges.

For example, from North America, one can fly business class to Easter Island on LAN, with free enroute stopovers in South America for 80K BAEC miles, or one can fly from North America to Bali on Cathay Pacific with free Asia enroute stopovers, for 100k miles. In fact, the least enticing BAEC awards are on BA itself!