I don't have any experience with the .375 win. yet, but the round does intrigue me. I haven't run the ballistic program on it's possiblities as of yet either, but just looking at it in the manual with available bullets it looks promising.
At first glance, with a 250-255 gr. the .375 win ballistics would seem to run better than the .41-.44 mag class of rounds. The higher BC's of the .375 win. are going to carry the velocity much better than any standard pistol bullet, making it a very good modest range performer in my mind.
I think if you were to chamber the .375 win. in the Encore, have it throated longer and seat that 255 gr Barnes Original out (or not), you'll have a dandy elk round. Then I would go with the 220 grainer's that are available for deer and other medium game
The .45-70 is is an awesome round in 14-15" platform regardless. And there is certainly nothing wrong with .460 S&W. Both however are starting to push the recoil limits of most shooters without a brake, and I personally don't care for brakes much on big game rigs.
just my 2 cents worth
Dave
P.S.,, if you want clodbuster drop me a PM and I can run a couple theoretical loads on the program and see what that .375 might actually look like.