I haven't shot the 375 yet -- hope to soon. I've done some chrono work with the 325 SSB, and have had good results. I'm still working up loads, but I can tell you that about 90 grns of Trip-7 FFg will push the 325 out of my Omega at a very consistent 1640 fps (Std. Dev. of only 11 fps).
Buffalo Bullets also makes a 285 grn SSB, but I haven't tried those either. Don't know if I ever will -- the 285 has a sectional density of .200, and that's on the skinny edge of drop-em-dead-in-their-tracks. The 375, in comparison, has a whopping SD of .263 -- compare that to, oh, say a 245 grn PowerBelt at a pitiful .140.
According to Ron Dahlitz, founder and owner of Buffalo Bullets, the 375 SSB is their most popular saboted bullet. He said that the 375 SSB is a longer bullet with corresponding longer sabot than the lighter SSBs, giving more surface area to grab the rifling. He also said that the SSB, like other sabot bullets, is designed for faster twist barrels like 1:28. Mr. Dahlitz knows his stuff, and even went so far as to have the ballistic coefficient for the 375 independently verified -- it has a "real-world, G1 BC value of .296." (
http://www.chuckhawks.com/buffalo_bullet_king.htm)
Just for fun, I ran some numbers on the 375 SSB. If you push it out the muzzle at 2000 fps, you should have a six-inch kill zone point blank range of about 190 yards. At 200 yards, it'll deliver over 1900 ft. lbs. of energy, and over 2500 ft. lbs. at 100 yards. Now that's serious.
It all comes down to whether your gun likes them or not. Good luck and good hunting.