I've been doing a bit of reading on these two finishing techniques, both of which continue to be used by Fender (and likely other manufacturers), and I can't say I've come across any hard conclusions about them. The nitorcellulose allows the finish to wear, in the road worn look, where as in 30 years, a guitar with a polyurethane finish will look more of less the same as it did the day it was purcahsed (there are obviously limitations to this). So I guess I have a couple of questions: Is one inherantly "better" than the other, and will the finish on a modern guitar, manufactured by todays' process and finished in polyurethane actually hold up after, say 20 or 30 years, or will it yellow, chip, etc? And, if nitro is the chosen finish for so many Fender models, why do they continue to finish many of their guitars, including the Standard and even some CS models in poly?? Cheers.