This is definitely powerful software, but I don't know, I'm leaning towards purchasing WHS2011 and DriveBender I think.
My server has a bunch of drives, so I'd rather use parity, but I kind of hate the way that it doesn't seem to integrate with WHS. Now, I don't care about a Dashboard addin for the console, but reading the site / wiki, you can't actually control Users and Share Permissions from the WHS Dashboard, and instead have to do it from the FlexRAID interface. It kind of seems to defeat the purpose of WHS slightly for me.
Not 100% sure if that's what I'll decide, just what I'm leaning towards at the moment. This is definitely impressive though.