Well said nomercy. I don't think I could have said it any better myself. I have never used a ghost ring sight. I do however use the Williams peep sight. In the NE and NC parts of PA where I do most of my hunting and shots tend to be less than 75 yds. I opted to take the scope off my 1895 Marlin guide gun 45-70 and repalce it with the Williams. I've taken two buck and a nice black bear with this outfit. And an added bonus, the rifle weight was cut down.. And, if the peep gets knocked out of kilter for one reason or another, I can just unscrew the aperature and flip up the buckhorn rear sight and I'm back in business.
One thing you forgot to mention is the natural tendency for your eye to center the itself in the peep (or vice versa) which makes the peep so accurate. It will do the same with the ghost ring but accuracy will not be as gooddue to the larger dia. of the hole.