Have two friends that shoot the WSM's. One,the 270 and the other the 7.
The 270WSM comes fairly close to a 7mm Wby Mag but of course in a short action. I never could figure out why the WSM / WSSM's never got better press. To me they are all great in a bolt gun or single shot.
Some are definately better than others. On the good end . . the 270. On the bad end . . the 243.
The 270 and 7mm are both great choices for long range. Of those two,I would pick the 270 for its sectional density. --- SAWMAN