No.
.44 beats it seven ways since Sunday....
I'm sorry, but if you can handle a .357 Magnum and come away feeling "My .357 has almost no recoil," then you're a prime candidate for something more.
"I'm starting to feel that if a .357 is not enough, I probably need a rifle"
That's pretty much the reason Elmer Keith pushed so hard for a .44 caliber version of the .357. He wanted something that was "rifle hitting hard"/"extended range" - that he could pack on his side. Good as it was(is), the .357 magnum falls shorter than the .44 Rem Mag does at this task.
- Is the .44 "more" on the backend than a .357?
Yes. Most of the time. Most of the time it's more than most people can or want to cope with.
It sounds a lot to me, like you're in the same boat I was 30 years ago. My first 6 shots out of a .357 mag left me with a "Is that all there is?" feeling.
My first round of .44 Rem Magnum, OTOH, was like "Oh yeah! That's MORE like it!".
Where do the big boys realy stand out?
Raw horse power my man,,raw horsepower. You give up some of the lower end versitility,,,but make huge gains in the mid to upper ends. Already having a GP100 solves the lower end versitility. The .44 can pck up right where a .38spl ends off - and ofetn with less strain to both gun and shooter.
- Is the .44 more expensive to feed?
Unfortunatly, yes it is. Second to increased recoil, the increased cost of ammunition is the biggest trun off for most people. Handloading reduces it some, but even there the .38/.357mag is cheaper to feed.
- Is the .44 as packable (carry)?
Again, probably not - if you want to maximize power/ minimize package. IMHO, the best home for the .357 Mag is a small pocket revolver, like the Smith J frame, the discontinued Colt magnum carry or the SP100.
Sorry to be so long winded. Personally I think you're making a mistake by overlooking something more than the .357 Mag.