In 10-15 years the 270 and 300 WSM will be the top magnum sellers and move the 300 WM and 7mm Rem mag to 2nd place. The trend is already happening. The other WSM's are history.
I disagree. The cost of the factory ammo (WSM) is sky high compared to what you can buy the .300 Win Mag and .270 Win ammo for. Unless you handload it's something to think about. I passed on a .270 WSM because of what the factory ammo cost.