RE: fixed or pendelum sights
I use the Preditor IV with a Timberline No Peep. The Preditor is the dove-tail mount style which allows me to have a second Preditor bracket set up with ground pins instead of the pendalum. The dove-tail mount allows " quick release" type changing of the sights with no adverse effects on settings. The best of both worlds, practice on the ground with pins and hunting from my tree stands.
The Timberline No Peep" forces" you to use consistant form (especially helpful from the tree stand) and gets rid of low light problems associated with a standard peep sight. I did my final sighting in from the tree stand todayand am now ready for next Wednesday' s season opener.