The greatest masters of the craft abandon tools altogether, shaping metal with hand and mind alone
The exception is Sleight of Hand to try to find Lotus Bloom on Turn 1 in Ad Nauseam, with the flip side being many decks having an important two-drop to find like Baral, Chief of Compliance
Entering the battlefield tapped, this card is already at a disadvantage, which is made worse by its meager stats
We had done some (decidedly unscientific) testing with it, which we even made mention of in the June 2012 announcement
All that being said, in those games where I did get to untap with him with a Goblin Electromancer and maybe even a Guttersnipe or two in play, It was fun killing an opponent from 17 life with pings and other incidental damage and card draw
Mirkwood Bats Mirkwood Bats is probably a better wincon than Marionette Master, and it comes down for two less mana