I think I can probably count the number of upgrades I've had on my fingers. I was upgraded twice to Concorde, which happened each time a couple of days before the flight (as you ended up on a different schedule), with a phone call from BA.
The rest would have been one or two upgrades from CW to F. Don't think I've ever had a ET to CE upgrade and I practically never fly in long haul WT anyway (usually use Avios for leisure long-haul and have plenty to fly in J for both me and the Missus).