Very much real, and pretty awesome for the Dreamcast. It makes a lot of games better, even some you wouldn't think of trying to use the Panther Flightstick on (Star Wars Ep.1 Pod Racer), and great for Aerowings, Bang Gunship Elite, Airforce Delta Storm and the like.
I uploaded a video of my Custom Dreamcast Arcade Cabinets where I demonstrate the Panther Flightstick with some games.
You can see that video here- https://www.youtube.com/watch?v=sBCYo9Kn1B0
which you can see it featured at about the 26 minute mark in the video.
So, if you can find a MadCatz Panther Flightstick anywhere, it's highly recommended you get it.