Are you asking if a Cannondale is superior to a Trek?
Or are you asking if Cannondale makes superior bikes in general?
Both Cannondale and Trek make very good bikes and if you are comparing bikes in a certain MSRP range, then I think you'll find them very even in build and equipment group quality. It'll really come down to which bike you like to ride the best, can get the best price on, which bike shop you like the best, etc.