"Wrecked" is Buffy at its worst. It seems to be enjoyed by those who like their Buffy episodes "angsty" and "tortured". Unfortunately, this episode is just tedious. Willow's addiction to magic as a metaphor for drug addiction is extremely obvious, and grows wearisome very quickly. The show is all about metaphors, but they're usually done with much more wit and style than what is found here.
I love this show and in season 6, Marti Noxon, newly installed as a co-executive producer, just sucked all the fun out of it. The skill of Buffy the TV show was that one episode could have you giggling like crazy, whilst the next episode could rip your heart out. In Season 6, it was just all misery, all of the time. There were very few reprieves as every single character in the show hit rock bottom in some sort of way.
"Wrecked" was just one of many episodes in season 6 that saw beloved characters at their lowest. I appreciate the pain characters have to go through to achieve growth, but I also love the Buffy that can convey pain and growth through wit and bitter humour, rather than such heavy-handed metaphorical melodrama that Noxon delivers here.
On top of this, despite Buffy and Willow seemingly realising the spiralling nature of their lives and vowing to overturn it, still spend the rest of the season making the same mistakes and feeling miserable for it. So, really, all the pain experienced in this episode was useless, as they didn't grow from it. They kept coming to the same conclusions about their lives but not actually doing anything about it. For me, that renders this heavy-handed episode pretty much pointless, unnecessary and uninteresting.