Cylinder is "Not a Choke" but "Lack of Choke". By definition Choke in a shotgun bbl means constriction, Cyl has none. Well anything not exceeding .003" is I believe still considered cylinder, but not considered "Choke". A barrel is thus Not "Cylinder-Choked", but is Un-Choked or Not Choked whichever way you prefer to say it.
Now, to those of us fond of tight choked old hammer doubles, the thought that one of barrels is "Un-Choked" can be intensely bothersom, no matter how well that barrel kills.
However, I must admit that I like being able to take close-flushing birds quickly with chokeless barrel. Like another poster, I also use appropriately time between missing close shot with a chokeless barrel and waiting out bird for second shot with tight choked barrel -- this is an advantage of cylinder-full choke combos that is perhaps not widely advertized.
Niklas