I've hit Aer Lingus Concierge which means that I get guaranteed four upgrades per year, a companion ticket (companion travels free based on my booking, even if it's in Business) among other benefits.

I am thinking about switching to BA and reaching for a Gold card, however, I'm worried about the amount of free upgrades you guys get as there doesn't appear to be any guaranteed.

Does anyone know % wise the chance of getting upgraded and whether people from Euro Traveller get upgraded to Club often? (or even Club to First)?

I've heard some people say they get upgraded half the time while others have never got one despite being Gold for years.