I was present as well, nice event, nice goodies. I signed up for a 'regular' Amex back in November when the Brussels Airlines Amex ended. Time to evalutate what I am going to do with the Amex Gold card. Defenitely going to sign up with the Mastercard as it is much more accepted.

If I cancel (or downgrade) the Amex, do they claim the bonus miles back?

What I also like, maybe off topic, looks like they are going to launch a small business Mastercard as well, unsure if this will have any link with Brussels Airlines/Star Alliance. But very interested in this too to separate personal/professional spent.