I just wanted to say that the banlist shown on Smogon right now was for last generation. This generation's banlists aren't up on the site yet, though you can find them on the forums. Garchomp isn't Uber in the fifth generation. :3
Metagross's speed isn't useful enough to be Scarf'd, though you can certainly try Choice Band Bullet Punch and see how that works for ya.
I saw your post in my team topic and I think it'll help alot. I've one question though, could I use Metagross as a replacement for Flygon instead of Garchomp? Because somehow I don't really like Garchomp and Smogon classes it as a Uber too.