I have the Samyang version. It has an 8 bladed aperture.
It's a nice lens, gives good results, has reasonable build quality and is good value. Only downside is it's a bit on the large size - about the same size as a Nikon 135 f/2.0 (although it's a lot lighter).
Thanks for the reply. That's weird that it has 8 blades when I've only see it reported as 6. Even their website says 6. (Dead Link Removed) Strange. Yeah, I think I'll rent it and see if I want to sell my 35mm lenses and go for it.