The Weatherby is very well made and finished (in the Mark V version). The downside is that they are huge and thus heavy and with a 300 Wby you won't get a barrel under 26" (and that's as short as you should go on that case anyway). They are also less likely to have all 9 locking lugs perfectly mated top their recesses. The Savage, on the other hand, isn't as refined nor as well finished. The 300 Weatherby will do everything the 300 WM will do and will handle the heavier bullets just a little better than the Winchester.
I'm not entirely sure why you would want to use 200 grain bullets, particularly given where you are located. 180gr bullets will do the trick quite nicely on most species of North American game, and if you're using monometal bullets you could even step down to 165s with little fear. I believe that this is where the 300WM is better than the 300 Wby...with moderate weight bullets for caliber. With a 165 TSX you're burning a lot more powder in a longer and heavier rifle for not much gain in performance.
That said, there's no reason not to buy a 300 Wby in a Weatherby rifle if that's what you want. But you will be paying double what you would have to give for a Winchester M70 and not getting double the rifle. You could get a Vanguard for way less money but if you're buying a Weatherby then you'll find a Vanguard to be a poor substitute for a Mark V.