ToxicCharged :
Is the gigabyte worth the extra $50?
In a word, no. Why? Each uses a custom PCB but the same processor and memory. All that's actually different is the cooler and the amount of overclock out-the-box.
I've got the Gigabyte 770 OC 4GB and its great. But, I only bought it as it was the ONLY 4GB OC 770 available at the time. EVGA is a great maker and between these two, Asus, Zotac and a couple others, I'd always go for the cheaper one.
Both cards have similar overclock capabilities but the Gigabyte has a slight advantage due to the new upgraded 3X WindForce cooler. But, NOWAY worth $50 more!