Re: Benefits of a 1 meg volume pot?
I use 1M pots often.
They give you more of a "direct to jack" sound. They not only prevent as much leakage of high end to ground, but they also load the pickups differently, creating a higher resonant peak. They also give you much more "active-like" control, i.e. a much more usable sweep, instead of all of the usefulness being bunched up near the top for the pot. Go to linear 1M, and you take this to the extreme (in a good way IMO).
If you want to know what it's like to play a 1M linear volume equipped guitar, try a traditional Fender Jazzmaster. The lead circuit volume pot is 1M linear (though the tone control is 1M audio). The idea is that your "home base" knob positions are set with the knobs down a bit. Then you can add treble or remove it. With 250Ks, you are more likely to be running the knobs at 10, and only be able to remove treble, not add it.