I don't think there are any bolts in the system Gary Lee uses: the neck is held in place solely by string tension and, yes, an allen set screw accessible in the upper fingerboard raises and lowers it. If the strings are removed, I believe the neck will separate from the body; still, with the strings in place the instrument is quite secure. If you haven't already, take a look at the explanatory drawings on Lee's website. As mentioned in an earlier post, there's also a short video there showing the impressive system in operation. I think an adjustable neck would be very useful for, say, a touring pro who often finds himself in different climates, leading to possible changes to his action that could easily be corrected with this system. In a matter of seconds the player can dial in the precise action he wants with the strings under full tension. No need to remove the strings or fumble to adjust bolts inside the guitar. Personally, I'd gladly pay a small penalty in weight to have this luxury; besides, the added weight -- probably only a few ounces at most -- is centrally located on the guitar where it's unlikely to effect the instrument's balance.
2010 Andres Marvi (cedar/Madagascar rosewood)
"...beware of all enterprises that require new clothes..." -- H.D. Thoreau