Is this cartridge and rifle still loadable....worth it or not?

If you like it Yes to both counts although dies for .25 Rem may be harder to get, I had a set till last year, got big money for them.

I have one which belonged to my wife's grandfather, then father, in succession (and is now in the possession of my son). I found dies for it at a reasonable cost, but this was several years ago. I'm not sure that you couldn't load .25 Remington with .25-35 dies successfully, and the .25-35 dies might be cheaper and easier to find. .30 Remington brass is simple to neck down. The batch I have didn't even need annealing, trimming, or thinning -- just run it in the .25 sizer and load.

I settled on a 90 grain Sierra Hollow Point, since it would not be damaged in the tubular magazine. The proper charge of 3031 propels it to a bit over 2900 fps.

Since the Remington 14 has the unique spiral offsets in the magazine tube, pointed bullets can be used in it, unlike other tubular magazines. Any lead bullet would have its tip flattened and deformed a bit by being stacked base-to-tip, but I was thinking that if I ever ran out of my current batch of HP's, I would try a 100 grain Nosler Ballistic Tip. The polycarbonate-tipped bullet should hold up reasonably well in the tubular mag.

My Model 14 is scoped with a Lyman Alaskan, and give fairly respectable groups, less than 2 inches as I recall.

The .25 Rem does NOT have the same case form as the .25-35 Winchester although it was created to compete with that cartridge. Even the .25-36 Marlin is not exactly the same as the Winchester cartridge.

Yes it will pay to load and hunt with it. The cartridge and rifle are fascinating and effective WITHIN LIMITS.

You can form brass from .30 Rem brass (.35 Rem has a different, larger, case head) by simply necking down and trimming to length. You CAN use .25-35 Winchester load data.