The main thing I tell folks is that they have to be comfortable. Comfort is different for each player and only through trying things yourself will you know what works for you.
What I believe to be ideal is when the plane of the fret tops conforms to the curve in which the strings ring. This is a complex compound curve as midpoint and excursion changes for the same applied force (striking/plucking/playing) in each fretted position. Also, scale length, tuning, gauge and action height the clearance possible (action). A thicker string tuned lower vibrates in a wider arc when struck with the same force as a thinner string tuned higher and thus generally requires more clearance and more curve. Note too that fallaway for bends is also very important; fallaway is affected by action clearance and radius - the lower the action desired, the flatter the radius and more fallaway is required to prevent the first string from fretting out against frets preceding towards the bridge.
The player’s attack is what makes the string ring and travel, so this is crucial to take into account. The harder the attack, the more the string moves, the higher the action and more relief required to accommodate the strings’ travel. However, some players prefer a lower action than the amount of excursion their attack creates; these folks accept a certain amount of string noise as part of the recipe. String noise is when the string attempts to move with less clearance than created by the attack and the sound is fairly consistent along with the attack; this differs from fret noise, which occurs when the fretwork is out of level or sufficiently worn so that it deviates from the curve of the ringing strings. Undesired string noise is a good indicator for adjustment; fret noise is a good indicator for fretwork beyond adjustment.
The benefit of the ideal action is an action that is as uniform as possible for a particular set of string curves. This can result in better intonation in that the compensation can be more exactly adjusted for a more uniform string deflection to be fretted (although admittedly intonation is greatly affected by other factors, deflection must be controlled as well as it causes the strings core to stretch, thus raising the pitch of the fretted note).
Keep in mind too that the guitar is a compromise instrument, beautiful and fun, but a compromise nonetheless. A typical guitar is asking six strings to represent almost 4 octaves with one scale length. A piano uses a scale length for each note, longer with bigger strings for the lower notes progressively. And lastly, we are playing in Even Tempered Tuning, which compromises the thirds and sixths to favor the perfect fourths and fifths (chords with a major tird as the top voice as in an open D sound funny).
A note on imported Asian guitars - many of them do not use glue in fretting and the frets are loose. It is a good idea to run some thin CA under them.
Any guitar from any maker can have fingerboard distortions and truss rod effect issues as wood is unique and organic (and hygroscopic) and the forces of the strings, truss rod and gravity place compression on the neck as a whole. If the fingerboard and resulting fretwork deviate too much for the predicted path of the strings (and the player uses these areas), it is important to rectify them. Each neck is unique, some good, some not so good; I've seen good and bad from almost every maker, so I try to assume nothing and observe everything.