I used them in the .458 Win Mag for about 40 buffalo, and some portion of 30 pigs. Some other stuff too. What I found was that at close range thick skinned game they worked as well as TSXs, and probably a bit better. Stretch the range out and they slow down at a rate that staggers the imagination. Don't even think about shooting through brush with them, brush eats them alive. On balance I think Im better off with good lead based bullets. On the pigs it didn't make much difference what I used, but then again I was using a .458.
I've got very limited experience with .235 ESP Raptors in .375. My interest in them was that they basically match the trajectory of a .300 Win out to 500 yards and opens up a lot of possibilities for a one gun/load for everything scenario. Early impressions are limited to whitetail and blackbear. All I can say for sure at this point is that I've never seen animals bleed so much in my life. A little black bear looked like a blood volcano had erupted.
I have found them to be very easy to work up a load for. So far it hasn't involved much more than finding maximum, then loading 10 to see what they do. A curious observation is that the CEBs will take the copper fouling left by other bullets out of the barrel in a few shots. I'd love to know the mechanism involved there.