I've been natural calling since I was 10. Used to carry a box of a few diaphragms and a box call to help with locating. To many lost calls along with countless other lost things. Now I carry a gun and a bottle of water. I've called in 100s of birds and have been told by pretty much anyone I hunt with it's one of the most realistic sounds they have heard.
I would recommend others trying it isn't hard. That being said I will say I have hunted with a buddy where a bird would gobble to his raspy diaphragm call but not my voice.
I think like anything they have different tastes. I could carry 100 calls to get one to gobble but I'll just move on and find the next ones.