I'm doing some work on a 12-string acoustic guitar, and am planning to replace the nut and saddle. I need to raise the action a little bit for the E and B strings, and also want to change to a slightly heavier gauge, so I'll need a nut with slightly wider slots; the low E string doesn't quite fit in the slot as it is, and heavier strings will make this problem worse.
How much does nut and saddle selection affect tone? I like the tone of the GraphTech ones I have -- it's definitely better than the plastic nut and saddle that came with the guitar. But are there options for anything better?
The self-lubricating factor of Tusq material is very subtle, and though the tone is good, am I better off looking at a bone nut and saddle? Are there issues particular to 12-strings? (The tone on this guitar is quite good, although a little muddy.)
The guitar's pickup is a soundhole-mounted Fishman, so there's no undersaddle pickup to interfere with the acoustic sound.