Anyone ever fly on the Concorde?

I've been on it two times....... once at an airshow in France and once on a regular flight.
Take-off is kinda special if you sit half way the fuselage. You can acutally see the airflow on that wing and the turbulence it leaves behind (wake turbulence).
The flight itself isn't that much, it builds up it's speed slowly so you don't actually feel that your moving pretty fast. You will get a warning when you pass the sound barrier else you wouldn't even know it :-)
Landing is spectacular because of the delta wing. The aicraft is pitched up while doing approach so it is a strange feeling.

How are the seats and leg room? first class seating or not much better than coach?

Well, it has a very small fuselage.... only one hall way (wich is small) and not much leg room. The compartiments for the hand lugage is also kinda small so i wouldn't take to much.
First class seatings depends on the operator i guess. I think Air France only had one class.