SK Ragdoll has thoroughly pointed out all the disadvantages of Gyro Ball except this one: it only has 8 PP. The only advantage I see is it has the potential of reaching a base power of 150, but its so easy to switch out to a slower pokemon to sop up the damage once the move is revealed. And you only have 8 PPs to spare. A single 20 % chance Attack boost from MM would pretty much do the same amount as maxed out Gyro Ball. 85% accuracy is still reliable, and is not risky enough to use Gyro Ball.
The selling point of this set seems to be that it doesn't fear T-Waves, unlike Agiligross, and are not easily walled due to CB forcing it to use a single move. I could however see a Metagross with a similar set but with Leftovers and Meteor Mash doing the same thing. That will improve its durability, and give it an offense that certain tanks would fear (hippowdon, for example, doesn't stand a chance if Metagross has Magnet Rise up and attack boosts from MMash undermine hippo's stalling capabilities)
The selling point of this set seems to be that it doesn't fear T-Waves, unlike Agiligross, and are not easily walled due to CB forcing it to use a single move. I could however see a Metagross with a similar set but with Leftovers and Meteor Mash doing the same thing. That will improve its durability, and give it an offense that certain tanks would fear (hippowdon, for example, doesn't stand a chance if Metagross has Magnet Rise up and attack boosts from MMash undermine hippo's stalling capabilities)
