| this is where personal preference comes in.
it's a call between, too high and you find your right hand technique suffers, but you can have a lot of fun with the left(assuming your a righty), forming chord shapes, executing hammer-ons, pull-offs, etc, it makes it a little more exciting.
or too low and your either not going to get a decent sound or you'll find your left hand will get lazy and all you'll be able to do is slap and tap
i have an action thats suitable for both, but it has a lot to to with the bass i'm playing on, it has a very flat board, only a very slight radius, and hardly and relief in the neck, only a touch on front
it's a 5 but from bass side it's 3 1/2mm
and treble is the same, theres a slight camber as it progresses across, but not a great deal
what bass are you playing>?
i know for example on my old j, the action was quite high, but that was because if it was any lower it would rattle on 12>
experiment with the hight of your strings
if you have to make any truss rod adjustments, remember only a 1/4 turn and let it relax, also reintonate after adjusting
last tip, use a hair bobble/tie as a capo style mute around the 1st/2nd fret when tapping, i find that it stops any fray notes and gives a little more percussive style, give it a go, just experiment, everyone will have a different opinion on the best setup
stu | 
