RE: Extreme archery sites good?
I've got a couple of them... If you get one, make sure it's got the newer full-containment pins much like Spot Hogg's are. They also make a pin guard to protect a weak spot where the fibers can be easily snapped off in brush now.
My only real complaint with them is the size of the round pin guard; I like Spot Hogg's large pin guard (2 3/8") because it marries up perfectly with a 1/4" Fletcher Tru Peep.