I bought some of these 1 Meg ohm potentiometers when I had to buy some different materials that I thought I would need to do some guitar wirings.
I know that these were (are?) used in vintage types of guitars like many Fender Jaguars, Jazzmasters and early 70s Telecasters, so we are talking about a bright, cutting tone.
Well, believe it or not, they do deliver! In fact, they let your pickups, whatever they are, to keep more of their natural resonance, so the sound will obviously be brighter. Just do a quick search online and you'll find more infos about 1 Meg ohm pots. For me they are just great, if you want to make your instrument a little brighter, they won't disappoint you