It's worth lowering it a little, but 1) every bit you lower it hurts the camber curve more, because the front suspension gains less and less negative camber as it compresses, and the more compressed you start out, the less negative camber you get with the rest of the compression, and 2) past a certain point (generally considered to be about an inch, but somebody's got the specifics somewhere), you lower the roll center more than you lower the center of gravity, increasing the roll couple, actually increasing the amount the body wants to roll...beyond what it can, thanks to available travel, so bam, you get a nice insta-load on the outside tire for a net decrease in front traction.
Or something like that
Years ago I used to kick the autocross snot out of a guy with a 94 Cobra in my stock suspension 92 coupe. He went lower, lower, lower, stiffer, stiffer, stiffer...and slower, slower, slower....and accused me of cheating. Not much you can do with stock springs, bushings, control arms, K-member, and a set of KYB's, right?
And now, I take my bling-tastic MM-equipped car to an occasional autocross and get slaughtered by a guy in a rattle-trap 4x4 ride-height 83 GT. Seems maybe my skills have lost their shine