You mean the texture paints? If so, they work just fine. As usual, the main gripe isn't the quality of the product, it's the value. You can get textured acrylic mediums in a neutral color that's easy to tint with paint (or simply paint over) from Liquitex or Golden, or various pre-colored mixes from Vallejo, all in comparatively massive containers for a modest increase in initial cost.
[edit:] I wasn't aware that
GW had released half a dozen new paints, when I posted.
This thread has a few early reports, but I'd expect more and more reviews to start rolling in pretty soon. They look good from the promo videos, but that's the entire point of making them - any faults will only come out with widespread "civilian" use. I must say, though, I'd be sorely tempted to try them out if I was particularly looking to achieve any of the effects they give (except rust, as I've already got pigments for that - the blood and bile, however, look downright snazzy, and the cracked earth would make for spiffy basing, if expensive across a whole army).
