In my opinion, both calibers are very good, Im sure stubble and bigcountry know more about them then me, but I do reload for the 7mm STW and this maybe stating the obvious but with both of these being such high horsepower speed freaks, the STW that I reload for doesnt like lighter bullets, when you start loading the 139 hornady's accuracy goes out the window, Im sure the 7 ultra is the same because of the high velocity, the only other obvious difference is the STW is a belted round whereas the Ultra is not, I know some people have some complaints about all the Ultras feeding (for dangerous game) but that shouldnt be an issue. My 300 ultra feeds fine. If I had to choose I'd take the 7 ultra, just my opinion. Oh and as far as recoil a good brake will take that out of the equation.