Factory specs? Toss them away. Totally useless for modern radial tires. Factory specs have it set negative, which makes the car plow straight ahead all on its own. Good for bias-ply tires that tend to wander everywhere.
Go for about 2 to 2 1/2 degrees positive caster, 1/4 to 1/2 degree negative camber, and 1/8" to 1/4" toe-in. If your alignment guy can go even more on the caster (more positive that is)... go for it. That's where you're going to get that crisp turn-in feeling.
Oh, positive caster is where the top of the spindle points towards the rear of the car, negative points forward. Negative camber points the top of the spindle towards the frame -- positive outwards.