It's important to note that proxies are not legal in most organized play
The raw power of generating so much advantage for so little cost quickly resulted in Ancestral Recall getting restricted
On the other hand, Mystical Tutor is hand disadvantage in a matchup where that cannot abide, as is Vampiric Tutor, though the latters ability to get Energy Flux and Null Rod, or the creature side of the combo, makes it worthy of inclusion on the draw
To really make my point, I have to illustrate a common scenario in which you could find yourself during a game, where the use of this card could come up
With such an emphasis on the exile zone, though, we have to wonder if well see the return of Pull from Eternity or Riftsweeper to start building some machines
Every question has a proper answer