Are the GMPP Fast Burns heads better than the LT4 Heads?

[B'klyn9C1]

I read in the Sept. 2009 issue Chevy High Performance, in the Q&A section, that the current Fast Burn heads from GMPP are really an as cast version of the CNC-ported LT4 cylinder heads.

They alledgedly took the LT4 heads further ported them, tested them and digitized them and then used that tooling model as the new as cast Fast Burn heads with conventional SBC water passages.

So how much better are the Fast Burns to the LT4?

Do you think that they would be a good part of a LT1/LT4 build after a conversion to reverse cooling??

I was wondering if GMPP really made substantial improvements to LT4.

If those improvements are real??

What are the effects on performance as compared to the LT4??

Can those improvements be gotten by other means??