Adding mana rocks like Mana Crypt and Mana Vault will help speed up the initial ramping turns that are needed for this deck to start copying a ton of Adventure spells and bury your opponent in value
Its cheaper, and its arguably easier to pull off without losing tempo holding mana up
It might not be good against some sort of imagined enemy [that you are probably good against anyway], so it must never be good
I'll be in the booth with Paul Cheon covering all the action, and I can't wait to see you there!
He is great in ramp decks where he gets Mana Vault, Voltaic Key, Mana Crypt and of course lands and he is great in combo decks where he gets Lions Eye Diamond, Pyrite Spellbomb, Chromatic Star and many of the previously mentioned cards too
If youre staring down a large threat, casting a Stinkweed Imp can help buy you time