New cover for Starfire Angels

I am in the midst of redesigning covers for the Dark Angel Chronicles individual books. These will replace all the covers that have come before.

Here is a sample idea of what I'm considering doing with them. Each will be slightly different but not by much. I may still tweak this one, but it's closer to what I had originally envisioned six years ago:

It's not character focused, so I'm not sure it will work as well for Young Adult, but I could sure use feedback. Change the cover to this or keep what I have? Would this stand as a professional cover? Is it good but needs a few changes--if so what adjustments should be made?

Thanks for your help on this.

Edit: Here is what the second book would look like:

And here is what book 3 would look like with the new covers, thanks to the input of some special artists:

And the last book in the series:

(Pretty much back to where it started, because I loved the cover for the most part.

As for Origins of Dark Angel, I'm still trying to decide on a central image for that. I'll update this post when that's determined, as I've been doing as I tweak these.

Update (12/29/14):