Many builders are new to music, so here are some thoughts about what makes an instrument function better from a musical perspective.
String Height: The distance the strings run above the fingerboard is called string "Action". Guitars that are played in the lap style using a metal bar to fret the notes have high action. They usually have no metal frets, but just lines across the fingerboard.This style is popular with Hawaiian and Country Dobro Bluegrass players.
For the more conventional style of holding the guitar, the action needs to be low. This makes fretting the notes easier. Furthermore, understand when you push down on a string to fret a note, this actually bends the string causing the note to play slightly out of tune. If the action it too high, the guitar will play way out of tune. On an acoustic guitar, a correct string height at the 12 fret is about 1/8".
Neck angle to the body, string gauge, tuning, nut and bridge height all affect action. Guitars with a truss rod installed in the neck makes it possible to make adjustments so the guitar plays in perfect pitch. When the guitar plays the correct notes on any fret on any string, the guitar has good "Intonation".
Please share any thoughts you have about String Height. http://youtu.be/fN_31o3PAYw