RE: 30-06 vs. 270 WSM
I have said the .300 wsm is the new .30-06, a great all around in my opinion.
For elk I like having the option of heavier bullets that the .30cal will allow, ie 180grs, vs. the .270 maxing out at 150grs, 160gr if you handload.
Personally I would get a .300wsm shoot 180grs for everything and call it a day.
I think for an all around I'd stick to either of those .30 calibers, since you didn't mention the .300wsm, my pick would be the .30-06, but if you add it to the mix, then my choice would become .300wsm.