Halo 5 on X1 doesn't run a constant 60fps @ 1080p. It has dynamic resolution from 1152×810 to 1536x1080 to help maintain 60fps. It still has drops. The majority of the game is well under 1080p. Not to mention the content is roughly 5 hours of gameplay. They sacrificed resolution and content for an arbitrary frame rate. So essentially the game isn't a 60fps worth having unless you only PvP which then only few people may notice the difference.