I haven't used one so can't tell you the "pros". However, as has already been mentioned, there are several "cons". My approach has been to simplify as much as possible to keep Murphy at bay. You are on the right track with HHA (Large single pin sight with luminous ring) and only need a large peep to complete your set up. Center the luminous ring in your peep and the highly illuminated pin becomes easy. Just my 2 cents....bow magnifier is akin to military intelligence.....
