Boonweaver Giant from Magic 2015 is a functionally better version of Auratouched Mage. He gets to search your graveyard, hand, and/or library for an Aura card, then you put it on him. Even though he’s 7 mana, which is one more than Auratouched Mage, he can search more places. He’s also a 4/4, so he’s a bit tougher than his predecessor. The downside is that, unlike Auratouched Mage, if he’s removed from the board before that Aura can be attached to him, the Aura simply goes to the graveyard. So, he’s both better and worse.
Of course, if you play either of these cards, or both, alongside a Commander like Bruna, Light of Alabaster, this won’t matter. Bruna doesn’t care where your Auras are, whether they’re in your hand, in your graveyard, or attached to one of your other creatures. So while Auratouched Mage may be better about ensuring a card ends up in your possession no matter what, Bruna’s not going to care as long as you got that powerful Aura (say, Eldrazi Conscription, Corrupted Conscience, or Celestial Mantle) out of the library and into a place where she can grab it. If you’re playing a deck like Zur the Enchanter or Krond the Dawn-Clad, however, Boonweaver Giant getting killed is a bit more unfortunate. At least you get the Aura out of the library.
Boonweaver Giant is never going to see play outside of Commander. Seven mana is just too much for a card that’s little more than a tutor in pretty much any other format. Heliod’s Pilgrim at common is much more cost-effective. In fact, the Pilgrim is even better alongside Bruna than this Giant. The Pilgrim is better in Zur and Krond, as well. Boonweaver Giant has definitely been included in Bruna decks over time, but that deck doesn’t play a lot of creatures. To be honest, a 7 drop is a stretch when you already have Auratouched Mage and Sovereigns of Lost Alara at 6 mana each. It’s the tutoring effect that you care about, really. It’s still playable in more than a few Aura-happy decks, just for purposes of redundancy - a feature that’s important in Commander.
Unfortunately for the Giant, Auratouched Mage has continued to see far more play in Commander. Boonweaver Giant is rarely seen outside of Bruna, and even then, the Mage continues to supplant it as the more popular option. But, if you have an Enchantress Commander deck, it can’t hurt to give it a shot.
(P.S. Also, people like to play Boonweaver Giant in some Karador, Ghost Chieftain decks. Not really sure why. )