Hi community, I'm about to buy a new gpu, i play in 1080p, now with a zotac gtx 760 amp, but i want to upgrade it, i would like to introduce myself with oc experience, is it worth the zotac gtx 970 amp omega or amp extreme edition? or just the reference? (I7 4770K non oc, gigabyte z87x-ud3h, 16gb ddr3 1600mhz corsair vengeance)