There are a lot of little things that go into making an exceptional guitar, and I enjoy taking care of those that I think really make a difference.
The term "playability" is pretty vague, and it covers the whole experience of how the guitar responds. I'm fond of saying that "a good instrument practically plays itself".
Since your left hand works the hardest, good playability starts with the neck and fingerboard.
Traditionally all classical and flamenco guitars have had flat fingerboards, because that is the easiest to make. But a "crowned" fingerboard---convex surface---fits the shape of your index finger better when playing barred chords.
The difficulty in making a crowned fingerboard is that it gets quite a bit wider as it goes up to the body of the guitar, and the curve of the crown has to flatten out in order for the strings to stay the proper height. The fingerboard actually has to be the shape of a section of a large cone, instead of simply being rounded.
My best friend's wife calls me a "gizmologist", and true to my nickname I've made a "gizmo" to help make my fingerboards just the shape that I like. They are crowned to an 18 inch radius at the nut and a 28 inch radius at the 19th fret.
Most players say that the left hand action on my guitars is easy, but they don't notice the crowned fingerboard until I point it ou to them!
Wood selection plays a large part in making an exceptional instrument, and the wood testing videos cover the tests that I use for selecting soundboards and backs. What I don't mention is that the best woods for these, and all the other parts of the guitar are what is called "quarter sawn" or "vertical" grain. That refers to the orientation of the growth rings as viewed from the end of the board.
I guarantee my guitars against defects in materials and workmanship "for the life of the maker", and I come from a long line of ancestors that lived to a very advanced age!
The "free 10,000 note tune up" goes with all of my guitars. It simply means that after playing the instrument for a time, you may find that it would be nice to have a few things adjusted. Maybe the action is a little too high, or a little too low. Perhaps the string spacing at the nut is a little too wide for your hand. These are things that I'm happy to change to your preference.