Personally, I love the explosive nature of "Operation Metro", for the very reason that no one is left out of the action. No vehicles makes the game more interesting, and you wont get through 20-30 seconds without being shot at. The kills are great, the xp is great, and 24/7 metro servers are typically full, given the ping is okay. You'll see a lot of YouTubers who love the Metro map, and I'd love to see this as one of the Rush maps. ZLO has blacklisted the only active American server (to my knowledge), so NRNS is the only server with decent ping and good amount of players.