ADL is useful for JPEGs - especially in high contrast situations. ADL Low does not adjust exposure so it does no harm. For those who use post processing that honors camera settings - like View, Capture, and Photo Mechanic - ADL is useful for RAW files. If you use Capture NX2, ADL can be changed in post processing although the exposure adjustment is final when the exposure is created.
In my testing, I found ADL creates and applies a complex curve that is hard to replicate in post processing.
I see little advantage to using ADL with Lightroom other than the in camera benefit to JPEGs in high contrast situaitons.