...And the SAA platform is what the .44 Special was "meant" for as well, they just didn't know it at the time! --and by its time of introduction (essentially lengthening the Russian) the .45 was too well established and may have worked better as a BP round anyway. Advance to the post 1900 age of smokeless and its a different story--or can be.
To the gent's comments about the .38-40 and .44-40, great rounds, comparatively, but there are sizing and lubing issues over and above both the .45 and .44--and in the day the "-40s" ran together with the Special (1910s through 1930s) before reloading issues or rather, comparatively, complexities, were as apparent, the Special had a stronger case as well...but, again, too late for the "case" to be made for the Special and darn few .44s were made.
Regarding the same gent's mention of .41 Magnum, a great round as well and the only argument thrown in here that's a solid one (it being straight-walled as well and nicely sized, caliber-wise, for mid-frame guns--but guns, bullets (and complete factory ammo) are arguably harder to come by than the .44.
I think the point, again, about "perfect" was made relative to platforms out there that work particularly well for it, obviously..and for those--the DAs folks have mentioned as well as SAA types--the Special is that, perfect.