The metal base of the highback/heelcup does well to provide support and performance, but for a Cobra I would just recommend the NX2 SE's. Full aluminum is going to do much better than 15% glass/poly frame on the Fives.
Go ahead, drink that kool-aid.
FS: Forum Sauce 142 $200 plus shipping
FS: Flux SE30 $75 plus shipping