Great thread. I'll echo the ideas already presented - that they're both (special and mag) good, have both, but the magnum doesn't get as much field use as in the past. My .44s are all single actions and the .44 Specials (Colt, USFA, Cimarron/Uberti and a duo of Rugers) are just-right sized, delivering just-right punch--without being obnoxious about it--for most of what I need. When I go camping or tromping where particularly large/dangerous critters are likely--which isn't that often--the .44 Mag goes with me. Even then, it's mostly an excuse to continue to "justify" the gun and give it some fresh air! But seriously, both are good, it's just the .44 Special is "better" for 95% duty - for me.
In the midframe SA platforms which commonly chamber the .45 and .44 Special, I like that the .44 is very similar in ballistics to the .45 ACP for close-in SD, but that the .44 can be loaded up for significantly better longer distance/hunting duty. I also like the .44 Sp over the .45 Colt in these "common" platforms for the .44 having an extra margin for "loading up" (more beef between the chambers). And since happen to have the .44 Mag (that'll also chamber the Special) it makes more sense for me than the large frame .45 Colt, which would otherwise be a good platform with hot loads for that hunting/dangerous critter use. Otherwise, I have no doubt the large frame .45 Colts would be an equally versatile platform as the Mag for that heavier duty.
Finally, I have always thought that the .44 Special is what the Colt SAA "was meant for" - had they known it at the time...ie, had cartridge been available in its current smokeless configuration in 1873. By the early 1900s when the .44 Sp came to be, the .45 had such a foothold what with its 30+ year head start and its long Army contract history (and .44-40's 30 year history for that matter with its dual pistol/rifle chambering)...that the "little" .44 never had much of a chance to make its mark. Even so, IMO, a better mating of cartridge and gun doesn't exist than the .44 Sp and the midframe single actions.