"because of the "dream of Africa" drives your choice or is the .375 superior to the .300?"

No. I am not overly keen on the 300WM but do like the 375H&H. In Australia we also have Scrub bulls- some are bloody big and cantankerous- and Water Buffalo. In a lighter weight rifle like the Remington's and Browning's they make a good Sambar rifle. Not saying you need a 375 for Sambar but they do a good job on them.

Cheers

Greg