Dawn's creators are answering questions in the stickied thread in Freestuff.

At the moment, you don't need to invest anything.  She's free.  Or will be when she's available.  Which I'm guessing will be next week. 

Supposedly, she bends really, really well.  She's got more polys than Genesis 2, but fewer than V4 - she's meant to be used with SubD. They plan to have conversion utilities so Dawn will be able to use the clothing and textures you already have for other figures. 

With Dawn, they wanted to start over from scratch.  To make a figure for today's Poser and DS.  (She's weightmapped, so users of older versions of Poser are out of luck.)  The idea is a figure that works equally well in Poser and DS.  There will be two separate figures, but, they claim, it will be much easier to support both.  Supporting V4 and V5 now takes a lot of work, because they are two different figures.  Dawn is the same figure.