re: upgrading
using BAEC Avios points from full Y does work.
but... using $ is easier -- a couple of weeks ago I upgraded from discount economy to World Traveler Plus from LHR to JNB for GBP189, and it was definitely worth it for a long 11 hour flight. FYI - The BA 70J 747 configuration has NO good seats in regular economy. There are several good exit row seats on the 52J config.