The only conversation worth having is stock vs. stock. It depends on what year STI one is talking about. Any STI will soundly beat a stock LT1. And with an LS1 it comes down to a drivers race.
Rated 0-60/1/4mile? 2006 STI 4.9/13.2 2002 4th Gen SS 5.2/13.2
Magazine 0-60/1/4mile? 2006 STI
5.0/13.0 4th Gen 5.2/13.6
Dragtimes average 1/4 mile?
STI 13.4
4th Gen 13.4
That makes it a drivers race. AWD on the STI gives it an advantage 0-60 off the line. 4th gens makes it up on the back end (if they got a good launch).
There have been a few factory freak 4th gens that got down to 12.8, but that also seems to have happened with Subarus also. (see link above)