Depends on what kind of shooting we're talking about. Here's what Bob Brister had to say about cylinder in "Shotgunning: The Art and the Science": "I do know that at 25 yards a pure-cylinder barrel will throw one of the deadliest game-getting patterns you ever looked at, more efficient at that yardage than a full-choke barrel at 50 yards." In fact, if you look at pattern percentages listed for various chokes at various distances, cylinder is typically credited with 70% at 25 yards--which is, of course, the full choke standard at 40 yards.
If we're talking upland hunting, most birds are shot--not shot AT, but killed or knocked down and retrieved--within that 25 yard range, or not much farther. Which makes it a very useful choke for upland hunters. And the fact cylinder opens quickly helps make up for aiming errors average shooters might make at close range with tighter chokes. Or badly mangled birds, if they center them too close with too much choke.
