Heavy, with all the problems that go with it. Excessive forward string travel, even enough for the metal to peen the back of the rest on some lower brace bows. More chance of wrist slap. Slower arrow speeds.

They are metal. Unyeilding. The string makes a severe bend on each side of the loop causing premature wear and damage. I have seen many strings break exactly flush with the loop. And when that string breaks with a piece of metal screwed onto it, you have a really good chance of getting a pretty serious cut on your face or arms.

All in all, they're not worth the risk. In my humble opinion, that is. I'm sure there are some poor deluded souls out there that love them.

Use a good, stiff loop material and keep the loop well waxed. The wax keeps it open for easy, quick hookups and gives good wear resistance. And practice doesn't hurt either.

Once they're pulledtight, they don't move.