So I recently had a conversation with another call maker about this. I made the statement that not all premium calls are custom. In my opinion premium is defined by sound quality and playability. Being cosmetically right such as fit and finish is expected as premium but embellishments are not. I like to think of myself as being in this crowd. I'll tell you first thing I'm not building custom calls with the exception of custom diaphragms.
Now custom is something different. It's hand made regardless of method. No CNC products, but built one at a time or in very very small batches and extra time is taken to be sure it's nothing short of right.
I want to hear what others think of premium calls that aren't necessarily custom, and any flattering words for custom makers as well. There's a lot of guys who over the years who've standardized production and even some mass production calls that have met the premium status.
Both will do the job, but it all depends on what you are looking for in a call. IMO
Sound / Tone / pitch
Custom calls are usually built by turkey hunters. A good custom call builder will have a following of people looking for a better built call with a better sound quality and craftsmanship. In other words the turkeys like them. Sound / tone. It is what you are looking for in sound to your ear. IMO
Mastering a call / learning the call and how it wants to be played is up to the person who buys the call regardless of type and wants to put the time in to be a good caller... Cadence - what to say and when to say it ...