EVGA has a better service and is probably as good as Gigabyte for build quality. EVGA's warranty covers overclocking and other stuff that many others don't accept. EVGA's 580 offers a warranty upgrade to 10 years in Europe if you register the card and upload the invoice within 30 days. email EVGA for the info. EVGA support replys to me within 24hrs on working days.
Have you sure about Lifetime warranty by eVGA??? I saw a discution some 2 weeks ago that people where saying that you got 3 years warranty from eVGA too