ET Phone Home wrote:
I can't image that a string sitting in between a grove of metal will have the best tone.
It's really all just personal preference and it would only affect your tone when playing open notes anyway. Personally I'd just stick with the locking nut if you're not having any major tuning issues, then again it's a locking nut so if you are having any major tuning issues then it's not performing properly and may be stripped/screwed in some way ? If you replace the nut with x or y or z new material it'll only make a difference to open strings anyway and to be honest I think that in terms of consistency of tone it's probably best to have a metal nut anyway.
ET Phone Home wrote:
is it even worth doing the mod.
I'd say no honestly, it really won't make a startling difference to your tone if any, and that difference in tone would probably be subjective anyway. If you ever plan on selling this guitar then it's very likely that it would cause issues with resale value as most Ibanez players like trems and in the case of older Ibanez guitars featuring bridges like the the lo-pro any Ibanez fans who'd want to buy it would be happier knowing that the original nut is on there and hasn't been lost or replaced with some sort of lower quality generic part.