I've never been fond of the Sap or Blackjacks. My instructor in the course I've been taking is a former LEO and he absolutely loved his Blackjack.
I DO have a pair of Sap Gloves, they are marvelous things in my opinion. I'd like to get some fingerless ones soon, when I get back to Oregon. They provide padding for your hand while the weight helps follow through on the punch. Never had to use them, but they keep my hands warm in the winter...
"Today is victory over yourself of yesterday; tomorrow is your victory over lesser men." - Miyamoto Musashi
[Insert random irrelevant religious quote here]