Aside from the action and neck relief, another thing you need to consider are the level of the frets. The frets height will change over time, either due to normal wear and tear or due to prolonged exposure to extreme humidity conditions.
The friction of the strings will cause to wear certain frets out in the long run making the fret heights uneven. Aside from normal wear and tear, exposure to extreme humidity condition may cause changes to the fingerboard. In effect, changes to fingerboard may alter the placement of the frets causing uneven frets.
Uneven frets hinders an instrument to achieve an optimal setup for you will be forced to compromise action and neck relief to accommodate an uneven fret. In the long run, especially if you frequently use your instrument, the need to re-fret your instrument may arise.
What is a Plek Station? The Plek Station allows us to achieve a level of precision with setups never before possible with traditional methods. The Plek Station reads the condition of the frets and how level they are against the overall geometry of the fingerboard, and then shaves the fret wires down to a hundredth of a millimeter. This results in an instrument that not only plays better, but also sounds better due to the improved intonation and increased levels of harmonic content as the frets are much more finely cut.