I don't see where there would be a huge difference except I think the lamb is a bit leaner. I feed my P's feeders, beefheart, buffalo heart, shrimp, and other stuff. I think the buffalo heart is the best but not many people can get it. I get mine from a farmer who raises buffalo about ten miles from here.
One reason I like the buffalo the best is that they aren't pumped full of drugs like the cattle or other livestock.