Looks like the auto weighs nearly 200 pounds more than the manual they tested. Part of that is the lack of CCB, 64 pounds of rotational mass, part of that is the auto vs manual weight of 19 pounds as per cadillac.
That leaves over 100 pounds not accounted for. The only real thing I can see that is different is the pano sunroof on the auto car.
That figure seems about right for a dual pane sunroof. Seems like it's alot of weight on the top of the car.
Also I think the CCBs are going to be a large contributor to straight-line speed. Probably worth about 2 to 3 mph in the quarter mile. I would have gotten them if the replacement costs weren't so high if one gets damaged (I heard for wear they should last the lifetime of the car). Also interestingly some reviews have complained about the poor brake modulation in the CCB cars, however the steel brake cars don't seem to share that trait.