Metaethics sequence is a bit of a mess, but the point it made is important, and it doesn't seem like it's just some wierd opinion of Eliezer's.

After I read it I was like, "Oh, ok. Morality is easy. Just do the right thing. Where 'right' is some incredibly complex set of preferences that are only represented implicitly in physical human brains. And it's OK that it's not supernatural or 'objective', and we don't have to 'justify' it to an ideal philosophy student of perfect emptyness". Fake utility functions, and Recursive justification stuff helped.

Maybe there's something wrong with Eliezer's metaethics, but I havn't seen anyone point it out, and have no reason to suspect it. Most of the material that contradicts it is obvious mistakes from just not having read and understood the sequences, not an enlightened counter-analysis.