I agree with WA, Buffy might seem better as Faith, but I also think she had the way easier job of the two. First off, it's already a bit easier to play the pist off, sexy, evil vampire slayer than it is to play Buffy who is much more multi-layered and was established for much longer. I still think Sarah did a really good job though. As for Eliza, I think she did pretty spectacular for what she had to work with. It wasn't exactly Buffy, but it was close enough for me. I also think that the script had something to do with SMG's role standing out, because she had much more material to work with that was VERY Faith like. ED as Buffy didn't have as much material that was very Buffy like, so I think she did the best she could with what she had.