Calling it the Happy trigger is false advertising, btw. It should have been called the Ecstatic trigger.
It's pretty impressive. I told my gunsmith about it and he asked to see the rifle. I brought it in and after he measured the pull and felt the trigger, he spent awhile banging the buttstock of the cocked (but unloaded) rifle on the carpeted floor to see if he could get the hammer to fall as a result of the jarring. He couldn't ever get it to drop.