Regarding your question about which airline to use the points on - in the list I saw AirFrance (Skyteam), BA (OW) & Air Canada (Star) which seems a bit weird. I would guess that the airline you can choose is whoever gave you the points in the first place or maybe an alliance partner - the FT experts can weigh in on that.

In most instances, I cannot afford to fly Biz even though I like the extra space (as someone who is overweight). I have done 14-15 hour sectors in economy and it's not as bad as it seems. Having a quiet cabin without too much hustle & bustle makes it a lot easier - as does having considerate, clean co-passengers.

Having said that, twice this year I got the opportunity to pay for limited upgrades - you get lounge access & full cabin service without chauffeur service and mileage. On QR I paid $500 to upgrade to biz on NRT-DOH (almost 12 hours) and that was a no-brainer. It was great value for a really comfortable product (2-2-2 is completely fine when there is no one beside you ).

The other was a $1600 upgrade for Biz on EY from JFK to AUH. While this was way more expensive, I chose to go for it based on the following points
a) I was returning from a whirlwind trip to NY and knew I would be exhausted
b) I had a really hectic week at work ahead and wanted to be as rested as possible
c) A chance to try A380 Upper deck biz on a long-haul sector

I enjoyed both tremendously and would like to do it more regularly - that is based on its value compared to my requirements.

Also, I flew domestic F in the US because I had two pieces of luggage which would have cost me $60 on Delta and the fare difference was $75 between Y & F (SEA-LAX).

Ro