I loved this episode. One of my faves. I pretty much agree with all of the praise and the general "what's reality?" vibe everyone else has mentioned. One thing no one has mentioned, though, is how it sort of pokes fun of the viewers for getting all involved in this obviously crazy world. That was awesome. I mean, it did kind of say, "Gee... you guys must be nuts to suspend your disbelief THIS much!" The show also made fun of itself when it said that the plots were becoming unstable. lol.
As a writer, this episode really struck a chord with me. Hear me out. This might get a little weird for you non-writer types. Writers will probably know exactly what I mean.
Joss and the other people behind Buffy are first and foremost writers. All of these wild thoughts and metaphors and symbolism and everything that we love or hate about Buffy - all of the inconsistencies and continuity errors, even - start in their minds first. They do this for a living. So that means that while they're stuck on the 210 or the 101 on their morning commute, only part of their brain is on the traffic. The other part is where the characters live. A whole world of unwritten scenes is constantly going on there. Buffy's fighting a demon. Xander's declaring his love for Anya. Giles is cleaning his glasses. Some character from a side project or that half-finished novel is butting in and begging for attention. At just about any given moment, one of the characters is just sitting there annoying the crap out of the writer saying stuff like, "I would soooo never say that. Seriously. Give me a better line. And you're making me sleep with that guy? I have some taste!"
Like Buffy, the writer has a choice. The writer can take the 101 to the bland office building and have the family that loves him/her and the steady paycheck and the health insurance with the nice doctors who, if you pay them enough, might make the characters shut up and leave you alone. Or, the writer can live with the characters and try to do what he or she was put on this earth to do: write. That's a lot harder. The writer can still have the house and the family and maybe a doctor or two, but the reality is that that's a lot harder to maintain as a writer than it is in most "normal" professions. It's usually a thankless job. And most writers don't make it. You've got to be a little crazy to bet your daily bread on writing. So I saw the episode as Buffy making the hard choice. She chooses her destiny. She chooses the crazy, messed up world of vampires and demons over the normal world of family and other institutions.
So, yeah. Because I'm a writer, this episode really struck a chord for me. Maybe I'm projecting, but that's sort of what it's like to be a writer. Minus the nut house, of course. I've never been crazy, I swear. But Buffy's experience of talking to family and doctors and anyone else in real life while something else is happening to the fictional characters in her head is very much like what must happen to Buffy's creators while they're drinking their morning coffee.
All in all, I thought it was an awesome episode.