I use a 300WSM, and dipped my toes into the 270 Win (not WSM) waters this year again.
The 270WSM compares pretty similarly to the 270Win as the 300WSM does to the 30-06. A bit more speed, a bit more recoil, a bit more powder, etc etc etc.
Are you handloading for this rifle? If not, now would be a great time to learn. While the 7WSM and 325WSM are worst off for brass/ammo selection, the 270 and 300WSM's are still not as widely available as stuff like 30-06's, 270's, and 300WM's.
Getting tooled up to reload BEFORE availability dries up, to me, makes a lot of sense.
For the record, I shoot a fair selection of out-of-the-ordinary cartridges.... 7.5x55, 6.5x55, 30-40 Krag, 35 Whelen, 264WM, 257 Roberts, 300H&H, and others. A good reloading setup, if you aren't already doing it, is something I think you might be wise to consider.
Other than that, I like the WSM's. I have a 300 and it is a sweetheart of a rifle. All my deer rifles, with the exception of a Marlin Guide Gun and a 1917 sporter that was my father's, are Model 70's. They range in age from being produced in 1937 to 2012. They're all good.