I was lucky enough to fly it when BA announced the Concorde's retirement. BA put on a special deal when it was announced, otherwise I could never afford it.

It was essentially a tourist attraction by that time, but still worth it if you like flying. The whole lounge experience, the flight, etc, was memorable. I even managed to score the elusive seat 1A.

I still have the boarding pass and certificate stored somewhere. There're also many trip reports on FT that you can read.