Great thread... Some knowledgeable people have replied with some excellent responses!
One thing I would add, is that there are some sounds I am looking for a call to make. Whether it be purring, cutting, yelping etc...
What I look for in a call (whether friction call or mouth call), is one that makes the sounds I want to easily. If there is a call that makes the perfect yelp, but takes a degree of difficulty and skill involved, that I have to think about, that is not a call I want in my vest.
Granted, a scratcher does take some practice to learn... But I can now reach in my vest, pull out a striker and scratcher and make all the sounds I want without looking and without thinking about how to make those sounds.
I do NOT want to be thinking "now how do I make that sound again" as I have a bird unexpectedly side-hilling me on a "make or break" moment.
Unless I am eating, I always have a diaphragm call handy (generally in my mouth). I might switch diaphragm calls for different sounds, but every season I have "that" call that just makes the sounds I like easier, and that is the one in my mouth.
