i see a lot of posts about the difference in the 250k pots and the 500k pots. personally i hear the difference but its not too much as to really improve tone per say IMO
are you talking about humbuckers or single coils? (brand really doesn't matter much)
In a Gibson Les Paul or my SG I'll always use 500k pots....In a strat where I have single coils in the neck and middle positions and a fullsized bridge humbucker,I'll use the 250k..Single coils sound too harsh to my ears with 500k pots and the taper is weird for me.Strats are usually pretty bright anyway,so the 250k is usually a welcome in my case....I don't like things too bright anyway..The 250k values retains the warmth and smooths the highs for the single coils and I'm used to the taper of the 250k values in a strat..
john does about the same thing as i do. in the bridge with singles i tend to use 250k, but i a strat style with 2 buckers id use 500k. in gibsons 500k.
you can always roll back the tone control and lose some high end, cant really add more if ya dont have it