Why .44 Mag over .454?
When I bought my first .44, the Casull was around, but revolvers chambered as such were stupid expensive and all I had ever heard about was punishing recoil and intense muzzle blast. Plus: Big, bulky, heavy, generally ported or with a muzzle break.
I didn't need bragging rights or a show piece. I just needed a good sidearm for hunting/hiking/camping in bear and moose territory.
Why choose .44 Mag the second time?
Because I missed it. I missed having a genuine 'magnum' handgun cartridge that wasn't punishing to shoot.
Ended up getting the same revolver back, too.
And, as much as some people may say I'm missing the point, I agree with the guys that say if you're going to be carrying a sixty ounce revolver, you may as well just have a rifle.
For my purposes, uses, and applications, a five pound rifle in hand is better than a nearly-four-pound revolver strapped to my waste. (Shoulder holsters are not an option under most circumstances.)
I prefer rifles, anyway. I am not a handgunner.
Where that argument breaks down, is when people find out that I have a Blackhawk in .327 Federal, and a Super Redhawk in .480 Ruger. ...Because the 'little' 5.5" Blackhawk is heavier than the 7.5" .480; and I did, still, end up going bigger than .44 Mag.