Pilot Custom Heritage 912 (and for that matter, Custom 742 and 743) is all about their nibs. It starts off with a simple, functional, non flashy (non urushi, celluloid etc etc) body which has good size and ergonomics (good balance whether posted or unposted), as well as a simple converter filling system - the Con-70 converter with excellent ink capacity. After getting these out of the way, the real choice is the type of nib you want. Whereas many pen companies are "simplifying" their nib offerings, the 912 offers no less than 15 different types of nibs (EF, F, SF, FM, SFM, M, SM, B, BB, PO, FA, WA, SU, C, MS), all of them with different feel and writing characteristics.
I have the 912 with the FA nib which is the polar opposite of the PO nib in terms of softness. It is unique amongst the modern nibs. At first, I tried copperplate writing with it but its flow does not keep up. I have the chance to talk to the Pilot nib doctor, and he says that the proper way to use the FA nib is to do slow Kanji or Chinese character writing, which I find it really does with flair.
My very first fountain pen is the Pilot Birdie. Since I have re-discovered the joy of fountain pen writing again, I have tried many other brands, and now I have come back to Pilot once again. Its range is fantastic with even the cheapest pens (V-pen, Varsity pen) writing well. Its gold nibs and the variety that they come in is what really shines in the Pilot range.