I'm another one that thinks the game feels alot like Halo 3. Just now with the added classes/loadouts, there isn't that "OH **** LETS DO THIS" feeling when you see Team BR on well... I'll say Gaurdian since that was one map everyone mutually loved.
Once 343 introduces more game types/playlists, and introduces more maps, the game will start to return to what people were accustomed too, but 343 Industries take.