Not impressed. They had them on display at the GM booth at Super Chevy.
Unfinished ports, sharp edges in combustion chamber, .050"+ increment cutter path, etc.

Essentially they are heads that you will need to bench before installing and possibly retouch the seats if you accidently tag them.

I'm surprised at the low quality of them. They are cheap, but I guess you get what you pay for. I almost bought a set, and I'm glad I got a chance to see one in person.