RE: thoughts on 25-06 for hunting deer
If you already have a .270, I'd think about something other than a .25-06. Also barrel length only increases accuracy up to about 22" barrels, longer barrels are designed to give more velocity, hence magnums etc...impose 26" barrels. At first this seems kinda illogical, but it's true. I think a .25-06 is so close to a .270, and a .270 is one of the most accurate cartridges ever. 25-06 would be nicer for coyotes, than the .270, but what type of hunting are you looking to do? A 6mm Rem. will do almost everything a .25-06 will, though it's not as popular as the .243 Win, which won't do what the .25-06 will.
A step up from the .270 Win. in my book would be a .30-06, or a .300 WSM, I'd get the .300 WSM
.30-06 is the best all around, but do you plan to always own 1 rifle? If not, then specialize a little more would be my advice. If you own a .270 and a .300 WSM, you're pretty well suited for most in north america.
If you're just looking to deer hunt, some guys love the .338 Win. Mag. and that combined with a .270 you certainly could hunt everything in north america! I wouldn't worry about the kick of the .338 either, I have a .340 wby, and swear it kicks less than my .300 win mag. The .340 is more like the .338 Rem Ultra Mag, both are a step up from the .338 win mag.
A step down would be a .243 Win, or 6mm Rem, go lighter if you're thinking about coyotes/antelope. Bigger if you're thinking, elk, mule deer, moose, bear....
My advice, .300 WSM, .338 Win. Mag., .243/6mm, in any order. Tell us what you're thinking?