There are so many other factors involved that it is impossible to say. What works well on one car may not work on another. Driver feel has a lot to do with it as well.
A friend and I run cars of the same platform, and while I have my car set up a little to the free side with a touch of oversteer, my buddy's car feels "tight" to me, like it has too much understeer. Our lap times are always pretty close though.
My car currently has .01 degrees toe out. I've had more than that in it, but didn't like the results. I'm lucky if I put 500 street miles a year on it, so tire wear is not a concern.
