For what purpose?
SAS and SATA are different interfaces. 12GB vs 6GB is meaningless when comparing the Drive, its only relevant for comparing the Bus the data is transported on, and then only if the number of drives you have, and the concurrent IO is more than the bus it is connected to.
Sustained IO, or random IO?
Cost per TB or support and warranty or resale value?
Colour or noise?
Basically you have asked a nonsense question.