It wont cut it for most Vintage Cubes, as Sacrifice themes cant quite hang there, but who knows, maybe Warren Soultrader totally changes that equation
Rolling a 15 or higher lets you do it all over again
On arrival to the battlefield, this will tap for any color of mana but just that turn
If the spell has damage divided as it was cast, the division can't be changed (although the targets receiving that damage still can)
And then we also had countless ways to cheat effects out, like the cards below, Goblin Welder, Goblin Lackey, Elvish Piper, Quicksilver Amulet, Defense of the Heart, Sneak Attack, Show and Tell, and many more
I love using this at the end of your foe's turn with your extra mana and then untap and keep on keeping on