It should always be borne in mind that the function of the adjustable (truss rod) is NOT to cure any perceived shortcomings in the action, its function is to control the amount of string relief (the gentle concave bow found in the fretboard of almost all guitars).

If the action is too stiff or too low one should look elsewhere than at the truss-rod.

Personally I agree with mooman and prefer a well-made instrument with a non-adjustable reinforcing rod, like the old Martins used to have. With the advent of carbon fiber graphite these necks can be as slim and playable as those with adjustable rods.

Murray