The main probelm with the nut is the tendency to ruin tuning stability. With this in mind I've devised an actual test of how unstable tuning is with various nut types. The test is this: Take the tuning high, then carfully tune down to true pitch, being careful not to overshoot. Now give a gentle tug on the string to draw the slack into the main body of the string and out of the headstock. Now measure the tuning and see how many cents the note has dropped. This is the instability cause by the nut. The small the number the better. Here is what I find: Epiphone plastic nut: 16 cents (all average of twenty tests) Tusq nut: 11 cents Strat roller nut: 25 cents Homemade bone nut: 4 cents The Strat actually didn't surprise me. I've hated that nut since I bought the guitar and always had trouble tuning with it. A locking nut will answer everything of course, but it's a rel pain to use - unless you have a rack of guitars and an on-stage tech.