The question has been asked before. Might want to do a search. From what I recall, no one really knows about the fine cut mower and few dealers seem to carry it.
The fine cut mower is a deeper deck, and I assume has a mulching capability. However, it only comes in a 54" variety and is not self-leveling. Myself, I can get in closer to trim with the 60" and with the self-leveling, it cuts very, very nice.