I've watched all these videos, and looked at the Evertune website. I think I get what the system is doing mechanically to keep the strings in tune, and I certainly accept that in-demand session musicians need an instrument that stays in tune and has good intonation all over the neck. With all that said, I still feel incredibly dense, because I can't see what problem this thing is supposed to be fixing.
I'm an average ham-fisted amateur guitarist who's read a book on guitar setups and learned by trial and error how to set intonation, action and so on; none of my guitars are top-of-the-range hand-crafted professional-grade instruments, or have been attended to by top guitar techs to get them in perfect order. And yet I don't own a single guitar that needs to be retuned once the strings are stretched in. I can open one of the gig bags or cases in my cupboard now and take out a guitar I haven't played for a month and I know it will be in tune. I know this because none of them have broken tuners or worn-out bridge saddles or badly-cut nuts. If they did, it would be a cheap and easy fix to buy new machineheads or get the nut replaced by somebody who knows what they're doing. How am I missing the point of this bridge so badly? Can anyone help?
Is it really so rare to know how to set up a guitar in tune and string it properly so the tuning doesn't slip, and if so, why is a complex and counter-intuitive spring tensioning bridge system the answer, instead of learning how to set up a guitar in tune and string it properly? Not a guitar luddite, just genuinely mystified by the problem that Evertune purports to solve.