I just published a review of the Pilot Custom Heritage 912 with Posting (PO) nib: http://tina-koyama.blogspot.com/2015/07/product-review-under-rated-pilot.html I find this fantastic nib to be seriously under-rated and under-discussed! It's the finest nib I've used that is ALSO very smooth. It's relatively easy to find Japanese nibs that are extra-fine, but finding the smooth part is another matter. This nib gets my two thumbs up on both counts. Check out the interesting curve toward the paper: