I can't run a diaphragm mouth call. Never have been able to very well. I don't feel bad about that, either. I can yelp and cluck out of my mouth, naturally.
I've just never "warmed up" to using a mouth call. Never had a mouth call bring a turkey in for me, either.
Some people get terrific results with mouth calls. More power to them, that's great. I just don't want to be bothered.