Been playing guitar for 40 years and I can't say enough about the Evertune system. Once you understand it's dynamics. I change strings in a few minutes, wind them up, they pop into tune, I calibrate, they stay tuned... automatically compensating for string stretch. I can change strings right before a gig or studio session with no tuning worries. I can go into any temperature environment and guitar doesn't change tuning. I can go from practice to practice to practice with no tuning. It doesn't stop there.
Since your guitar basically stays in tune if you get into the habit of checking it each rehearsal all you are doing from session to session is fine tuning it even closer and closer to perfect tuning. When you use a capo it is pretty much normal to have to tune (for accuracy) at each capo position. Not the case with Evertune. Install capo and it compensates tuning.
I've owned a gazillion guitars, 11 currently, and the Evertune is pretty much my favorite of all times. It's a workhorse. The 2 caveats are 1, as stated, you are pretty much limited to standard tuning. You could tune to other tunings but what a pain. The 2nd issue is it dulls the strings just a bit. A little getting used to but I don't notice anymore. I have actually seen a bunch more guitars I would love to have but have held off on purchasing because they 'weren't' Evertune guitars. About to check on having a system installed on one of my favorite Strats.
Setup is as sweet as a guitar can be, again once you understand how it works (which is simple). It is a highly accurate setup. Put it this way. You won't regret the bridge.
Oh one more drawback for some. No tremolo. I was never any good at whammy bar anyway so no big deal for me.