I have been asking for dry/straight guitar tracks on a couple of projects lately. The reason is that when everything is coming together, many times the guitar tone just won't sit in the mix.
The bottom line always comes back to the gain. You just can't get that ballsy tone for rock when the guitar signal sounds like ten pounds of gain stuffed into a 5 pound bag.
I still remember doing a demo for a Starsearch audition. The song was pretty heavy and I was trying to get a Priest/Scorpions sound. I was in the studio saying it doesn't sound "mean" enough. I kept messing with the pre-amp gain and my tubescreamer pedal. After about 15 minutes, the engineer came into the recording room and very calmly backed the gain, bass and treble and turned the amp balls out. We then recorded the track 4 times switching guitars. It was hard to play, but the track was killer. best tone I ever got. We multed the guitar tracks and split them wide stereo. I then recorded the track with a ton of gain and we brought that up just under the others so you could just begin to hear it.
I also like to leave any FX until the last part of the mix. Chorus is nice, but can take over a mix.
Nick