Garchomp will be owned by the Lati twins, Kyogre, Groudon, Deoxys-A, and Manaphy in Ubers (ideally), but it can ideally kill Rayquaza, Dialga, and Palkia before they can make a move.
I personally like Garchomp, and I'm not too surprised to see it get promoted/banned, since its base defenses are...