It’s past my bedtime, so I won’t be able to generate any original content for you. I can, however, quote myself. Here’s a tangent I took in Zendom tonight, when Seema said VOY was easier to write because of the plot-hole spackling opportunities:
I don’t think VOY had an unusual number of plot holes. The thing I find easy about VOY and hard about BtVS is the episodic nature of the show. You can’t just sit down and write a Buffy story - you always have to place yourself in the Buffy timeline. It’s not just the arcs, but also the characters coming and going. First Oz then no Oz, first straight Willow then gay Willow then Evil Willow then recovering Willow, Angel/no Angel, no Spike/bad Spike/pet Spike/Spuffy, no Tara/Tara, no Anya/Anya/engaged Anya, etc.
There was one character switch in Voyager - Seven in for Kes. Fic from the Kes era is rare indeed. If you block out C/7 like most fans do, then there was one relationship change in VOY - the P/T wedding, and there was marginal P/T for most of the fan-active seasons so you can gloss it over easily. Voy, TOS and TNG had a fixed situation (starship explore explore explore) that made it easy to write a story. I thought of it as the Eternal VOY Now - that moment between The Gift and Endgame (or for jetcers, that moment between Resolutions and Shattered) in which almost all fic was set. If you happened to have seen Drive you’d call Tom B’Elanna’s husband instead of her boy-toy. If you happened to have seen Imperfection you’d write the Borg Children off the ship - but those were minor points. Mainly you thought “how about Voyager hits some kilometer long space avocados that burn out all the whosits, trapping J/C in a turbolift together? Yeah, that would be a good fic,” and you wrote it. You never got Jossed, until the finale.
Strangely enough, though, this reset-button Eternal DQ stasis of Voy tended to lead writers to do the unepisodic - kill off the characters, settle down in the DQ, blow up the ship, stage Maquis rebellions, let all the babies be born, and of course, get the ship home. None of that, if it began in the Eternal Now, was considered an AU.
I’m still not an expert on Buffy, but it seems to me that when people write BtVS, they tend to get all psychological and vignettey, because anything you *do* is an AU the next week. Any little misstep also an AU makes - a petty little AU, not a broad and sweeping AU. (For broad and sweeping AU, see MJB’s Revolution: http://jemimap.cjb.net/voy/mjb/.)
When I think of good Buffy fic, it’s usually fic that has somehow slipped into the Eternal Now, mainly by forcibly eliminating the normal BtVS world. Yatzee wrote Phoenix-something that dealt with Buffy’s experiences in the far future. If you kill off all those complicating rotating characters, you get a sort of Now out of it. And there was Jintian’s fic about Faith - if you, again, cut out the main cast and follow someone off-screen, you get a Now. Anna’s Demon Noir throws the show into a demon dimension in which the Scoobies are relatively minor characters and Spuffy-noir is big. In all those cases, you have to simplify the show - or remake it in your new, orginal image - in order to really *write* something at length. I haven’t followed DS9 fic enough to comment on that - maybe Seema can tell me if my model fits. Voyager certainly always left you room for a novel or two’s worth of plot. XF must have been the same way, while Mulder was there. UST is so Eternal Now.