hehe, why so difficult, gather your friend, gather geetars with same spec, different colours, play with same strength/dynamics and what ever factors there can be
play all open strings single note. Record into your computer, analyse the waveform, enlarge the waveform until so big that you can see whats going on from the initial attack to the eventual decay of the notes
after that, find another innocent fella, ask them to listen to the recorded notes, ask them what they think, without letting them knowing all the conditions set when doing the recording.
most importanly, must play only single notes without context of music, no melody involved, just random notes produced by geetar, without progression/direction.
afterwhich, hopefully we can deduce whether finishing affect tone, at what frequency, to what extend, will it cause signal degradation, frequency loss, frequency boost, more mojo, less mojo etc
if the above sound stupid, pardon me