Originally Posted by
Globaliser
The moral of the story: Do not UuA from economy.
(UuA from economy can make sense for a limited subset of passengers, but this is a good rule of thumb.)
I guess this is particularly pertinent on short haul trips.
And on long haul, presumably the best bet is a WT+ before UuA? Is there any distinction between UuA at point of booking, and retrospectively. In terms of Avios/monetary cost?