This is the worst game mode ever created.
Picking other people's champion creates a horrendous atmosphere as it just leads to ALL chat rage. The MMR system is very biased. Picks and bans are boring because you'll never see anything besides melee and tanks. This is basically a 2.0 of dominion just on summoner rift just because your opponents can pick what you play. The only useful tool it creates is for game champion development where the non-popular champions are played.