Originally Posted by Mileometer

Thank you! That's really useful information.

Are the upgrades restricted to specific fare classes within Economy/Business Class or are even deeply discounted fares upgradeable? Also, if you use upgrades from, for example, Y to J, do you earn Avios/TPs based on the cabin you book (Y) or the cabin you fly in (J)? I suspect that that I know the answer to this but it's worth me checking