Originally Posted by
Globaliser
One big question which ought to be answered first: What is their travel pattern? Many of the OW schemes have a minimum sector rule. So if your friend were to decide that AA is easiest, but never flies anywhere that AA goes, they could be very disappointed if AA enforced its 4-sector rule and they didn't actually earn any status.
AA has been enforcing the 4 segment rule for a while now, as does BA, so that is the first hurdle to jump. Otherwise the ease depends on your flying pattern and the best bet, if things are stable, is to work out the alternatives for the past couple of years of flying. If you are changing your flying pattern then you will just have to do some analysis of the expected pattern. There is no simple answer, though if you fly in J/F on AA a lot then BA works out quite well!