The color-intensive mana cost is certainly a drawback but theres a good chance we see the return of Fetchlands in Dragonstorm, which would solve that issue
The Ur-Dragon The Ur-Dragon is the classic go big Dragon commander: even from the command zone, Eminence makes your Dragons cheaper, which adds up fast and lets you start dropping threats earlier than people expect
Its not limited to sorcery speed, either, so you can do this in response to removal to change it into a copy of a Legendary Equipment, sending the original to the yard
Reaver Titan would be a good card to put into a vehicle or artifact deck, along with Belisarius Cawl
It essentially lets you create a list thats then compared across the buylists of multiple big-name retailers, and it suggests where you might want to direct your attention
I'm a huge proponent of evasion in a lot of decks, and many times it's for your commander anyway