I can't comment on the sales, efficiency, or popularity of the 325wsm as I have no experience. I do know that when the 325wsm came onto the scene that it was a shot in the arm for those of us who enjoy shooting our 8mm niche rifles. I have a modern action 8x57 and the bullet selection (while small) is better than its ever been. Suffice it to say that the 170gr Hornady SST has turned my 8x57 into a bad mama jama of a deer rifle.
I agree. I thoroughly love the 8mm caliber.
I jumped on the 325 WSM not long after it came out. Have enjoyed hunting with it, and it drops pretty much everything like the Hammer of Thor hits it. I know it's WAY overpowered for whitetail, but it's nice to have that power when a 300+ lb feral hog wanders up.
Hornady 195gr Interlocks, 200gr Accubonds, and 220gr GameKings all work well here.