The Super Blackhawk and Blackhawk are built on the same frames. Blackhawks have aluminum alloy grip frames and ejector rod housings, but are the same size as the Super Blackhawk. The Flat Tops are built on the mid size frame for the .357 and .44 Special, large frames for the .44 Magnum, .45 Colt and .41 Magnum; not sure if there is a .30 Carbine Flat Top.
The mid size frames are much like the Colt SAA or New Frontier in size and handling.
Maybe so I'm an oddball, but I do prefer the XR-3 RED grip frames of the bigger Blackhawks over the smaller XR-3 grip frames.
(I know, I know! The XR-3 duplicates the Colt, but I'm not all that fond of that grip, either. Especially with stout loads.)
Bob Wright