I think the point is that the 270 wby is loaded hot right out of the box and the 7mm RM takes a little bit of judicious handloading to get it up to performance. I imagine that in the same bullet weight, with top handloads, performance would be similar in both.
For my purposes, the 270 with 130s would fit the bill perfectly. I have a 300 mag so I am not worried about the need for heavier bullets.
