You're comparing the 325 to the wrong cartridge. Compared to the 300 WSM the 325 shoots the same bullet weights only about 50 fps faster. It shoots the same bullet weights to the same speed as 300 WM. With a little more recoil than 300 WSM and about the same as 300 WM. With a 200 gr bullet in any of the 3 you get very similar numbers out to about 100 yards, then the 30's take over and they penetrate better at any range.
And if you compare real world numbers of 30-06 to 338-06, 308 to 338 Fed, and 300 WM to 338 WM you'll find that the 30's beat the 338's for all the same reasons.
It's not that the 325 or any other 8mm won't kill stuff. The 325, or any of the 300's will shoot flat enough and hit hard enough to take elk out past 500. They just don't offer a single advantage. I went through a stage where I was into and bought some oddball stuff to hunt with and have no problem with others who choose to do the same. But being different is the only reason to choose one. Once I figured out that my 308 would kill all the same animals a 338 WM, 300 WM or 325 WSM would kill I sold all of my bigger stuff. Makes life much simpler. Simple is good.
Not true at all. Any caliber bullet of the same brand and type is of the same construction. I realize this is hard for some to wrap their minds around but a 6.5mm/140, a 7mm/160, a .308/180, a 8mm/200 and a 338/225 will all give almost exactly the same penetration on game if they are the same brand and type of bullet.
Unfortunately Winchester has never offered any of the WSM's in a light, compact rifle and while they list it, try buying one. It isn't readily available. They are all roughly the same size and weight as their standard rifles. You'll save 2-3 oz, but that isn't much. Kimber is the only manufacturer who made a lightweight rifle chambered in the WSM's. And in rifles that light magnum recoil is stiff. And I don't think Kimber ever made a 325.