i'm not entirely convinced the variable volume fire chamber on the epihany isn't a little gimmicky...
if small volume gives quicker recharge, why not just design the thing with a small chamber in the first place?
what advantage would there be to a larger chamber? i guess it gives a lower operating pressure - but is that really needed?
when you are looking for a tourney marker that can shoot fast and consistently are we not just looking at how quickly it can recharge and therefore cycle?
i know, i haven't answered the question, but it gives you something to consider....
All depends on the type of paint, weather conditions etc.
You want lower pressure for brittle paint or sometimes on cold weather, higher for tough paint etc.