Metagross has a base stat total of 600 . Which makes it a Pseudo Legendary Pokemon
Bronzong has a base stat total of 500.
Now,If you want a Pokemon with exellent Defenses, Bronzong is the one for you.It has nice Attack but its Sp.Attack is low.Its movepool is big.you can do everything with it and its pre evolution can be obtained early in the game.
On the other hand,Metagross has monster Attack and Defense.Giving it a big advantage in battle.Its Attack can reach to 405 It maybe be a little hard to get but trust me,every single minute is worth training this Beast.Again its movepool is very big.Bigger that Bronzongs.Its low speed can be combined nicely with Gyro Ball.
So yeah, Metagross it is.