[Q] MSI Lightning 7970 3GB vs Sapphire 7950 3GB

I'd say Sapphire Vapor X over MSI Lightning (assuming similar or better pricing), but Gigabyte WindForce x3 over Sapphire Vapor-X (also assuming similar or better pricing).

Sapphire's card consistently overclocks a little better and has a somewhat more quiet cooler IIRC. Gigabyte has a slight overclocking advantage and is often the cheapest along with a cooler that has the best noise to cooling ratio, granted it's not necessarily the coolest nor the quietest.
 

EzioAs

Distinguished
Why don't you ask yourself why you're getting an expensive card in the first place?

To me, I pick the MSI Lightning because I've seen reviews showing it has great overclocking capability (granted not all cards overclocks the same) and I like the Twin Frozr cooler a bit more than Sapphire's Vapor-X (some reviews indicate it cools good overall and silent as well).