Of the bank's size ($47.6B in assets), NYCB CEO Joe Ficalora doesn't seem too worried about growing to over $50B - the line at which regulatory scrutiny could be stepped up. He notes recent comments from Fed Governor Tarullo that $100B is probably a more relevant line which should be crossed.
NYCB multi-family lending is distinguished from peers in that the majority is for buildings with rent-controlled units, i.e. below-market rents. This makes those properties less likely to face vacancies when the economy and credit cycle head south. It's a big factor behind net charge-offs averaging just 0.04% since coming public in 1993.