They're the best I have seen or worn. I get drilled with straight, uncaught high-80s fastballs and I do not feel a thing. It's not like when you get drilled the Honig's or other ordinary shins, where you feel like your kneecap is cracked. It's absolutely the best protection you would ever require.
I stole mine in an ebay auction that nobody else participated in, but even at regular price, I would jump at them.