Paul Harrell has a few videos testing them in various calibers. I saw nothing that would persuade me to switch from a traditional HP. All they do is punch a clean, caliber sized hole through the target. Now as a barrier defeating choice, or dangerous animal round they may be excellent, but for any other use I see no advantages. Underwood makes excellent ammo so it's not a matter of them being poorly manufactured. But having seen a deer shot close up with a Hardcast 357 and watching the deer run away with a clean little 357 hole through it, I can certainly attest that non-expanding bullets have a limited range of use. EDC not being one of their strong suits...