Cylinder, or certainly nothing tighter than IC, are more valuable chokes than most people realize. The late Bob Brister, comparing IC and full, wrote: "Full choke is a demanding mistress; improved cylinder a forgiving friend." And he had good things to say about cylinder too:

"I do know that at 25 yards a pure cylinder barrel will throw one of the deadliest game-getting patterns you ever looked at . . . " And Mr. Brister looked at a lot of patterns.

Doubt that I'd want a gun choked C/C unless it were a pure woodcock gun. Some choke in the tight barrel can come in handy. But the combination of cylinder and the right loads will put a lot of birds in the freezer. And it's really all you need at American skeet, assuming you're shooting at least 3/4 oz of 8 1/2's or 9's.