It's not a large issue if you don't plan on heavy overclocking, but the Z77A-G41 only has a 4+1+1 phase design which isn't particularly ideal. If it's just a light overclock then it'll be fine, but if you plan on adding a high-end aftermarket cooler in the future, you may struggle to add for voltage.
Also, I'm pretty sure the Gigabyte 7950's are voltage locked, this Sapphire card would probably be a better choice.
my experience with shapfire(had 2 cards) = bad quality they all died after a year . my friend has an 7870oc edition and i told him to not buy shapfire. well he has. and now he has blackscreening because of some wrong capacitors in the back of the pcb... and if the voltage is locked you can still do a voltmod on the card still i cant say anything bad for the 7950 from shapfire because i didnt had it in my hads yet