I agree with a lot of what the others have said Dirt. All I do is track. The most important thing I look for is feel. The all important groove. I recently did a track where I had worked out a partial break and when I tracked it it sounded pretty good, but there was a pretty sloppy run right at the end. As opposed to recutting and taking the chance on losing the feel I let it go. Benoit I definitely agree with. If you have extra tracks dedicated cut several solos, pull from or use the one that seems to feel right to you. Try some improv and some worked out material. Always remember that most of the listeners don't play guitar so what they lock in on is feel. This kind of skirts your question. I hope it helps