Hi, "once you've been windsurfing for a while, winds below 14 knots aren't much fun" is exactly why I bought a Tornado. In our area, once spring is over, the wind doensn't blow hard very often, I've found the Tornado is great entertainment when it's relatively light air, especially single-handed.
I've never seen an A-cat so no opinion there.
Good luck
Al
ps. the Tornado is great entertainment 2-up in heavy air as well, and not as physically demanding (I guess I'm getting older after all).