The biggest difference, to paraphrase Anand (I think), is that ASUS has such a large in-house engineering and design team to offer what apparently, nearly no one else can match - their own designs. ASUS (other than right during product launches) relies the least on reference designs. If this is something you very much would like to have, then ASUS is the way to go. Their coolers are usually very quiet and efficient, their VRMs are usually somewhat beefed up from reference designs, and other small things here and there. Because they do so much engineering and design in house, they are able to undercut a lot of competitors who use reference designs on price.
EVGA is a much smaller company, they don't appear to have the same fat engineering team. That means most of what EVGA offers are much closer to reference products.
I don't take sides one way or the other, but if you want something more reference like, with a bit of OC-flair, EVGA is usually good to go (unless you want AMD). If you want something usually quieter and non-reference, go for ASUS.
Other than that, you should consider MSI. They have their Gtx660 Frozr edition with the super quiet cooler that is on par with the ASUS DCII gtx660 as per Techpowerup reviews. It is also an excellent card.
Beyond these factors, you should consider what kind of a case and cooling setup you have or plan to have. The reference blower coolers don't require much intake air, because they directly exhaust to the outside. Because of the way the exhaust is directed to the outside, you can stack them (SLi) without worrying about circulating hot air. Blower coolers (reference designs most of the time) are excellent in low air flow cases and when stacked. Open air coolers like the DirectCU coolers or the Frozr are excellent when there is plenty of case air flow (front fan directed at the cards, rear PCI brackets open or meshed).
Facebook
Twitter
Instagram