What mike said…
Op. Metro is a very linear map, its RUSH thats how it is. Unfortunately being beta as well, more people are playing with guns and messing around figuring stuff out rather then using a tactical plan, every now and then you get with people who have been playing since it opened and are ready to kick some ass and its a lot more fun.
Conquest, what makes Battlefield, well battlefield is amazing, huge map with 64 players (For us awesome PC gamers) the depth in the game is just unreal, the scale of the map is amazing and its not even the biggest map in the game. Rush is not battlefield, rush is a bad company thing that they brought over into the Battlefield Series, I do enjoy rush but it is much to linear at times.