After experiencing how pleasurable the Esterbrooks are, I'm buying a dark grey Esterbrook J. I have a choice of nibs. I can get the 2550, 9556 and 2556 for the same price or a 2048 for an additional ~$50. At the moment I don't have an additional $50 (and as a leftie, I wouldn't have much use for a flex nib anyway), and I think that the 2556 is just a weaker version of the 9556, so that's out of the question too. So I managed to narrow the choice down to the 2550 (firm extra fine for bookkeeping) and the 9556 (firm fine, for fine writing). I'm looking for opinions and experiences. Which one should I get? How well do they perform? Is either of them scratchy?