Beekeeper,
I can't comment on the .375, but I am in the process of getting accustomed to a 550 American in .458 Win.
So far I have only fired 350 grn. loads, and am working my way up in bullet and charge weights.
I am impressed so far in the ability of the rifle to be comfortable. I have had to adjust the trigger(easy to do), and will start glass bedding it this week. I would recommend this step strongly, as I have heard the stock splitting stories as well.
I suspect that the action will need some "slicking up", and the feeding will need a bit of attention, but I am still impressed with what you get for what you pay. Hard to get a magnum mauser with a drop box magazine, decent express sights, and adjustable trigger for this kind of money. By the way, mine will take six down in the magazine.
Hope that this input helps with your decision. If recoil is an issue for you with the .375, this rifle should be a pussy cat!
Best of luck!!! :-)