Killed a bear and several deer with them. Then had one not open after a pass through on a very nice 10, and I haven't used them since. I found it stuck in the ground closed up with the O-ring still in place. What looked like a slam dunk shot ended up in an unrecovered buck.
That's just one person's experience one time, so I'm sure they are still a great head...that experience just caused me to lose confidence in them. They were plenty sharp out of the package, and always flew like field points.
NWBuck