I've got a bunch of wingbones I've been making over the years. Some sound good, some sound like gobbler yelps. I swear when I'm practicing with it at home I sound fantastic but then I'll use it in the woods and think it sounds like garbage. Sometimes I do get responses to it but not as often as I'd like.
Mostly I use mouth calls but have been using a glass over slate more this season. I have more control over changing the tone and cadence of a string of yelps with it than with a mouth call. Plus mixing in purrs and cuts seems to be easier for me on a friction call than with mouth calls.
One thing I've noticed with mouth calls is that I can only make really raspy yelps. That's not a bad thing but I can't get those clear yelps that some can. Raspy yelps have led plenty of gobblers within shooting range so I guess it's fine.
The best turkey call is whatever you're most comfortable with.