Thanks, Lt. Bob! I guess I'd rather re-record an instrument again if I didn't like the original sound or effects than to go synthesized later in order to try to get that magical, unique sound my amp, speakers, instrument, and good mic provide.
If you like the reverb on your real guitar, say, to begin with (or distortion), maybe it doesn't need to be changed later on. As far as other effects or editing techniques (EQ, panning, volume, automation, extra effrects like delay, etc.), all this can be done later on over your live instrumental track, anyway, even if it is using soft synths.
Or you could record your guitar "clean" through your amp speakers (via mic) and add computer effects later. But at least you get that rich depth, tonal clarity, and frequency range that only a real qaulity amp/speaker/guitar can provide.
Mike