I love them. All GWs Nurgle stuff has been consistently brilliant.
The skull cannon/chariot I'm not sold on - I would of preferred the cannon to look more like the old Epic one (and I might model mine up like that anyway).
The Tzeench stuff is... Well. It's GWs Tzeench stuff. It's odd looking, and not in a good way.
Slaanesh's offering is, we'll, just a big deamonette. Not much more I can add to it really... Except that it has stupid hair.