Do you mean newer in general or to LJ? I'm new to LJ as of January 07, but was writing Highlander crossovers with an OC about 10 years ago on usenet (my haunts were alt.tv.highlander and alt.startrek.creative)! My older ones were in the Trek universe, my newer Highlander crossovers have been with Torchwood and the Dresden Files.
"I think LJ-fandom as a whole - across various fandoms - has an aesthetic that is readily identifiable: tight third person limited POV (and often only one narrator per story), present tense, shorter paragraphs, character-driven even in heavily plotty stories, heavier on dialogue and sex than on action
I don't agree 100% with that, or not in relation to myself. I write in a variety of POVs and not much in a true present tense but I'll cheerfully admit to writing character and dialogue driven stuff; I've always had a tendency to write like that.
Part of me is uncomfortable that I seem to be finding that Highlander crossovers, and their writers, are being slated just because they are crossovers. Even on usenet back in the 1990s I liked to read crossovers, sometimes preferring them to 'straight' Highlander fic which I found staid and lumpy at times. I'm also one of the few people who actually seems to not like Duncan/Methos as a pairing; that's not new as I never really have done, though that's probably because I don't find Adrian Paul particularly attractive.
Maybe I'm just odd...
I find ff.net quite a scary place so I don't set foot there very often.