Anyone succesfully use an m.2 to PCI-E converter to add a 7th card to their rig?

I've got some Gigabyte ga-z97x gaming 3 boards that work with 6 cards and an m.2 ssd installed. The Biostar TB250 that is coming out can probably do this too.
Is it possible to use the m.2 slot for another graphics card with one of these adapters?

http://www.microsatacables.com/pci-e-1x-4x-card-to-m-2-m-key-4-lane-pcie-slot-adapter