I agree with learning to use all 3 types and bringing them with you.Many times I've had birds respond to one call,box for example,when they wouldn't with a mouth call or slate...and vice versa.You can call real loud with a box call and they work good for a locator to get birds gobbling.I also like to use a mouth and slate at the same time to sound like at least a couple hens are waiting for him and of course once they close the distance it's all mouth call then.Have taken birds I'm sure I wouldn't have if I'd only brought one call along.A couple/few different mouth calls is a good idea,the birds some times like the sound of one over another...I like Primos double/triple reeds.