It was stated above:
With premium bullets like CDP, Partition or TUG, SWIFT A-Frame... you have an equal cartridge to the 375H&H with better accuracy and less problems to use it in a standard Mauser 98 system. On the other hand you can realize reduced loads close to the 8mm Mauser!

I agree with all of that except the part about better accuracy. I have made a lot of 375s in my life as a gunsmith, and I personally am on the 2nd barrel of my 375H&H and the accuracy is excellent. I get groups at 100 Yards with 4 shots that all touch with my rifle both with 270 and 300 grain bullets, so I can't see how a 9.3 could be more accurate (considering I am also shooting a 4X scope with a 2 MOA Dot) My 9.3s (all 3 of them, ---- may soon be 4 too.) are also very accurate with my Ruger #1 in 9.3X74R being just as accurate as my 375H&H, but none beat it and the other 2 don't match it. So far I have not seen many rifles that do beat it, and I have owned it since I was 23 years old. That's 41 year now.
To be honest a sub MOA 9.3 or 375 is delightful, but any accuracy you get under about 1.5" is largely just "feel-goodies" and of no real-world value for hunting any game you'd actually hunt with such calibers as a rule. Most men anyway. maybe I am a bit "off" but it's not uncommon for me to shoot antelope with my 375 or my 9.3s. I have killed a few with my Ruger at over 400 yards, but even a 400 yd shot doesn't actually NEED a 1/2 MOA rifle and load.