I never use an artificial call. I use my vocal chords. After some prcatice I can do what any of those devices do. From a large buck challenge grunt up to a fawn squeal.
It can' t be that tough (I don;t think).
I can' t even muster anything that sounds like a turkey and some guys can do them excellently!!!! To me thats hard!
I never heard a can, but I' m sure that its a handy little unit!!
Tube styles work, but can sound " echo-ish" .
To each their own!