Most unaired pilots I've seen are not that good BtVS's unaired pilot and from what I've seen and gleaned from the script Life's unaired pilot kind of sucked.
There's the other end of the spectrum where the unaired pilots are actually quite good. And then there's the odd duck where the unaired pilot is actually better than the one aired.
Dollhouse's unaired pilot falls in the third category. No, really. It's actually better than the script I read.