I only tried it once, on my UD3P system, and basically it didn't do anything that I know of. It was originally supposed to make our hack systems able to use vanilla OS X, complete with "no problem" updates, but I think the project fell short of that goal.
The last post on the BIOS blog was last year, so I'm not really sure where that project is in terms of it being viable anymore. It was a neat idea, but as Carti points out in several posts on his blog, Apple tries it's best to keep people from using other hardware by implementing features in a way that prevents them from easily duplicating the results. This is a paraphrase, but that is the jest of what he is saying.
Also let me say that Apple has every right to protect it's property by any legal means necessary and I have no problem with that. I'm am grateful they left just enough room to allow the brightest members of the Hackintosh community to provide for the rest of us a way to install OS X on generic PC hardware. I am fully supportive of Carti's efforts and hope he continues to improve the BIOS to finally achieve his goal.