I assume the standard dead soft lead 45 Colt RNFP at 850 or so fps is not what we are comparing .Elmer had that to start with.He did start with it.Cylinder walls were too weak,and he hotrodded the 44 spl second choice.It worked out.
As has been mentioned,Ross Seifred has studied this some,his conclusion was he preferred to hotrod the 45 Colt in a Ruger,then he went and took down a cape buffalo to back up his choice.
My opinion,its a "shades of grey" issue.Given heavy hand;loads in a strong gun with proper bullets,both will do.
I enjoy plinking cans with full power 44 Magnum loads in a Super Blackhawk,Redhawk,or S+W 29.
I had a Freedom Arms 454 Casull in my custody for a while,and with full power .454 Casull loads,I exceeded my recoil tolerance limits.I found myself getting squinty as I squeezed the trigger.Marksmanship suffered.
I did have curiosity about the .480 Ruger,it seemed a sweet compromise,but I'm not sure it will stay with us.I've never fired one.
For my own limitations,regardless of power,I will be more effective if I do not exceed 44 Magnum or 45 Colt heavy loads due to my own limitations.
I think ,real world,the factors of bullet selection and ability to place the shot will be far more important than which label is on the box,.024 diameter difference,a .22 rimfire slug worth of bullet weight,or 100 fps velocity.