Yeah its all about where its comfortable for each individual. I personally like the call sitting back in my mouth where the front edge is about even with my second and third molars... Minus the wisdom teeth as I have proven that I been missing those for a long time!! Lol 
I been using diaphrams for turkey for almost twenty years and just placed an order with Torry for some of these calls. What I have seen and heard on YouTube, they are really versatile with unmatched realism!!! Even the old power howlers can't edge these diaphrams
