The only thing that's yet to convince me on this is that ur adding an extra step between instruction and the output.
It may well be the case that even besides this, u can get a good result with say 2x 4870 cards, but ofc it 'shouldn't' be as good as 2 in xfire. Only really cos xfire is AMD and Hydra are inserting a workaround.
xfire is still a technology that chipset or manufacturers have to ask or have an agreement in place from AMD in order to use it. Funnily enough like SLI. SLI ofc being the naughty frowned upon technology cos of it's source and xfire being the champion as they've got their agreements to co-operate in place with no issues at this point.
Naughty SLI, more excuses to be anti-green.

some1 should be counting.
Hydra tho, even tho it's an interpreter sort-of technology, may well produce better results, and not necessarily benching, if it presents itself to the OS as 1 card or gpu. That is the killer for the xfire/sli alternatives. Native xfire/sli dedicated software/games 'should' be better, but the Hydra would then offer the feature to all products.
Being Win7 tho is a total crock. There really shouldn't be any reason why this is the case, it's a choice to be that way.