While I have never owned a 7mm WSM, I have owned a 270 WSM (sold as it was rh and I am a lefty), and still own a custom lh 300 WSM (built when the cartridge was first announced); I do know that it is a great cartridge. It is too bad that it has not become more popular. I think the initial problems with feeding the WSM's scared people off of them. A problem that was easily solved by a divot in the magazine follower that allowed the short, fat cartridge to feed properly. Also, I think that the 7mm Rem Mag is just too entrenched in this category, and for the average person, the fewer options in factory ammo also deters them from the 7WSM. I am a huge faan of the 280 Rem too!
My Rem 700 B&C in 270 WSM had a slow barrel, and even with the 26" barrel only provided regular 270 Win velocities with the 140 gr bullets.
My 300 WSM is a 1/2 MOA rifle and has performed very well over the years. If I hadn't already had the 300 WSM and a big 7 (STW), I would have went with the 7WSM, as I personally prefer the .284 caliber over the .308 caliber.
The old timer I have been hunting with for the past 20 years has all 4 of the WSM's (Model 70 Featherwieghts) and his 7WSM is the most accurate of the four (and has the most beautiful wood).
Another friend in the Yukon has a 7WSM in a BLR and loves it for mountain hunting.
I too have read about all of the shooters in the target shooting sports that were having great luck with the 7WSM, as the more efficient case on the short action, with less recoil was performing very well.
I think that the current fad with the Creedmoors and the new 6.5 PRC is getting the most attention today, and the WSM's are fading in popularity right now. A shame, as they are pretty darned good!
At the end of the day, if you want a 7WSM, and you believe that it will provide you with what you are looking for, then you should go that route.