Howdy Cliff,
The US Army went to the Colt 1911 pistol chambered in 45ACP because they needed more firepower. The 45ACP is NOT a puny round, even by today's magnum mania standards.
The Cowboy 45 Special brass has the SAME internal volume as the 45ACP, uses the same primer and bullet. The ONLY difference is the rim. The C45Spl has the same rim as the 45Colt. Now, if that rim makes that much difference to you, shoot 45 Colt and stay happy. However, my Pietta Army 1860 open tops are too fragile to handle a full house 45 Colt load and would shake apart after a couple of matches. With the C45Spl and 20 grains of FFFg black powder under a J/P45-200 the guns will last a lot longer. No, it's not an ROA but I sure like the way it points and shoots. I have Kirst Konverter cylinders and a gated plates and Kirst ejectors. They are right handsome shootin' irons and I really like their fit to my big hands.
Were I to need something more robust I'd load up my brace of ROAs with strong 45 Colt ammo and have at it. For home defence I have a 12ga SxS by my bed. With 33.5 grains of smokeless behind a buffered load of 1.5oz. of #3 nickel plated shot, this would be my 1st choice hall sweeper.
So, yes, there's a place for light recoiling loads in SASS shooting and the C45Spl fills the bill nicely.
DD-MDA