If you handload, by all means go for the .270WSM. If you are restricted to factory ammo, the standard .270 Win is probably the better option. Ammo for the standard .270 Win. is more widely available and the conventional bullet loads are a lot cheaper. The Short Magnum has more performance capability, but the increase is nominal, maybe 200 fps across the range of bullets, given similar barrel length. I believe the Short Magnum has more accuracy potential given the short, fat case. But it probably is harder on barrels, and certainly the factory ammo is harder to find and more expensive.