I would say it depends on what kind of rifle you want to build and to do what.
My .25-284 was bult as a light Mtn. Rifle. At 7 lbs, 2 ozs. it even works as light varmiter. It will shoot Hornady 75 gr. V-Max's into groups that run in the .3's. But, because of it's light weight, I can barely stay on a 10 in . target @ 400 yds. from a sitting position.
If you envision a maximum range, flatest shooting Pronghorn/Deer rifle, then the .257 Roy will work a bit better. It has about 300 fps. on the .25-284. More blast, much less recoil than a 7mm Mag, shorter barrel life (1200 rds.) and surprising power at the shorter ranges. Built to weigh maybe 9.5 lbs. like my partner's, I have no trouble staying on that same target at even longer ranges. E

I have both, a 25/284 on an Alpha and a 257 Wby I did up a few years ago. .......Love both of them! The 25/284 is a bit lighter but just about ties the Wby. in velocity with 100 grainers.
The Wby. is built more for the longer ranges, longer barrel and a heavier Zebra wood stock.
Either one is ideal, so which gets used depends more on the terrain and expected range of shooting.

~Arctic~

If you need a testosterone fix or want to impress someone, then do the 257 Weatherby.

If you want something equal to a 25/06, but carry something different than someone else, then do the 25/284.

If you want efficiency, why not just do the 257 Roberts instead, or the 250 Savage.,

I have a friend who loads a 257 Weatherby, and shoots a 100 grain bullet. I load and shoot 260 Remingtons, and 6.5 x 55s and 6.5 x 57s. My 6.5 bores, ( 7/1000th more diameter, 257 vs 264) chronograph about 100 fps less than the Weatherby.
The amount of powder it takes me to be a 100 fps slower, is quite a lot less.

My barrel life is about 500% or more of what the Weatherby is, or will be. The trajectory difference has to be measured under a microscope to tell any difference.

If I had a cash bulge in my wallet that needed a new home, I would take the smaller caliber and spend more of the money I saved and will save, by not shooting a Weatherby, and invest in a lot better scope. The nice thing about a better scope is that you won't have to rebarrel that, in a couple of seasons like the Weatherby would be ( if you are a serious shooter).

Good luck any way you go and have fun.