Thanks to the NDA testers have to sign you'll have to wait till she's released to hear from them whether she's actually better than V3, I'd give it a couple of weeks from release day before buying so the early adopters can put her through her paces & show off all the wonderful new bits. So far she's not looking that spectacular to me, apart from the Emma character/texture which looks really good & almost worth buying V4 for alone.

Windows 7 64Bit
Poser Pro 2010 SR1