I have a boker plus Rhino, and I love the hollow grind on it. To my preference, I like all small knives (including folders) to have a hollow grind. I like all my large fixed blades (including choppers) to have convex grinds. All knives in the middle (4.5-6.5") knives should have full flat grinds. Convex grinds have great edge support and retention. Draw back to me is, they never get as sharp as a hollow grind edge will.