Let me preface this post by saying that I have not seen Wicked yet (but I am seeing it on Wednesday), so I'm using previous performances by these 2 women...
To answer your question about the comparison of Idina's and Eden's voices, they are similar with a couple of exceptions. Idina is a definite belter, that's a given. Eden is a belter as well, but it's been my experience seeing her in Brooklyn 7 times that she never seems to need to breathe. You will see what I mean when you hear her sing "Once Upon a Time" from Brooklyn. I am predicting that contrary to another thread about Idina's gasps and auditory breathing, that Eden handled her voice control much better.
I think Idina's voice is very smooth and velvety. Eden's voice is a tad bit richer and not quite as deep as Idina's. I am also expecting that Eden's acting was superb. That is a talent that she brings to her performance. She has a seemingly innate ability to draw you into the story and genuinely care about the character she is portraying.
I'm so excited that other people had the opportunity to hear Eden prove herself today. If only I had been there to witness it. I'm keeping my fingers crossed that she'll fill in for Idina on Wednesday...
"You act like you're cleaner than the Board of Heath, but you're just a fame ho just like me. You know it...and you LOVE it!"
-Paradice to Brooklyn