I haven't written for other fandoms, although I have read some fanfic in other fandoms. And two things have stood out between other fandoms and this one (aside from the obvious differences of other sorts of characters, pairings, and situations, as mentioned above).
Both of these differences have already been mentioned, as well. The first is that yes, this fandom has well-edited stories and that makes a HUGE difference in my willingness to read something.
The second is that the nfic is separated out and unaccessible to underage readers - that isn't always the case. And I'm not sure I'm going to say this so that it's clear - I like reading nfic, mind - but the majority of the LnC nfic that I have read is... not depraved, gross, or - well, you probably get the idea. I stumbled onto some nfic in a different fandom that was hardcore porn, and it pretty much tainted my perceptions of the fanfic written for that particular show.
~Toc
