The real issue up to this point is that there has been more market drive for solutions with more functional blocks than ALUs.  I expect this will change heavily within a year if we levy some of the major silicon suppliers, or some of you that have been in this from the beginning set up a business model that could rival the giants.  FPGAs and ASICs designed with mining in mind would offer substantially better margins than any equipment out there now.

As far as GCN goes, I have a tahiti, and have not found it to be substantially more efficient with current software options,  Of course until you an get a transistor by transistor map of what is in a chip, there's little to be said publicly about how to improve an option.  Though bitcoin mining of course favors clean manipulatable logic cells over all the fancy bits in modern silicon solutions.