I love the .257 Roberts. Mild recoil and I run 100 gr bullets at just over 3000fps with excellent accuracy. Very lethal on deer and pronghorn.
Like you, I have owned .25-06's. Can't say anything negative about them either, but if I want to go "bigger" than the .257 Roberts, I have an arsenal of .270's, .280's and .30-06's to choose from. Never really saw any reason to keep the .25-06's.
That being said, if I were limited to just one rifle, the .25-06 would receive strong consideration.
Both my kids started on the .257 Roberts.

WB