I have two CZs with single set triggers...and I LOVE THEM. As other posters have said you simply push the trigger forward to set it otherwise it is a 4-5lb pull. Both of mine are a little different. My 22-250 is about a pound once set. My 6.5x55 is about 2lbs when set. I am not sure how they would work if you spot and stalk but for stand hunting you can not beat it. When using it you simply set the trigger and put the crosshairs on your target and pull/touch the trigger. You do not have time to get nervous and if your rifle is sighted in you should make incredibly good shots. I looked into buying single set triggers for my other rifles and was stunned at how much they cost. Needless to say I did not buy any of them but in the future will not buy a rifle without one unless of course I find another Browning BBR in GREAT condition.
I do want to make one more observation...they can be VERY dangerous if you/the shooter is not careful. I would NOT recommend allowing a youth to use one...simply too dangerous.