I've turned to this card as I've looked for more ways to support a lifegain archetype in Orzhov. This might sound incredibly stupid but chasing lifegain as a deck theme has lead me to thinking about certain payoffs and support, eventually brought me to test Unspeakable Symbol. If you have a lifelink creature and just throw a ton of counters on it, you can quickly recoup what you invest into it (provided it doesn't immediately die). Gifted Aetherborn fits that curve nicely (I predict that the recently released Nullpriest of Oblivion will likewise play well with symbol).
Gifted Aetherborn was a good role player when I ran it. BB cost was nice for Gray Merchant of Asphodel and the lifelink was important for fueling Necropotence. I cut it at the beginning of this year for Mire Triton. Nullpriest of Oblivion is another new card that fills Gifted Aetherborn's role.
Incidentally this comment seems kinda hilarious in retrospect, considering Nighthawk Scavenger.
[180 classic cube]