Here is the thing. IF you use a peep for hunting you will lose some shooting light. A peep is going to be more accurate for shooting dots at a target. I've used the Timberline No Peep and Perrys. Both work. They absolutely show torque. Just the slightest change in hand placement will show up.

Some people can shoot just fine without a peep of any kind. Its all about being 100% repeatable in your form. I disagree 100% that they are a gimmick. They do work. If I was a target shooter I would use a string peep. If you are hunting you do not need to robin hood arrows but need to be consistent and be able to see better the first part and last part of the day. IF so give one of these systems a try.