Ken Forkish's book seems to have caught the attention of many TFLers recently, myself included. I haven't yet had the time to bake any of his levain formulas, but I did manage to make his Focaccia Genovese using his 80% biga white bread. I was pleased with the result, although the 1/2 cup of olive oil he calls for is too much - it was pooled on top of the finished focaccia and in the pan when the loaf was removed. Next time I'll go with about 1/4 cup. I suspected 1/2 cup would be too much but I try to follow recipe amounts as written the first time I bake a particular recipe.
Here's a picture of the crumb from the bread I baked with the same dough. It's one of the more delicious white, non-levain breads I've eaten.