Healing three damage for a single cost on two different Identities is great! Requiring both of those cards to be in Alter Ego at the same time is not so great.
I've included this card in both Miles' and Gwen's decks throughout the Sinister Motives campaign and have yet to play it. Both Miles and Gwen both have cards and abiliites that help them avoid damage, so the healing hasn't been critical during gameplay. Heck, at the fundamental level it is usually unwise to have both of your Heroes on Alter-Ego at the same time, allowing the Villain to stack a huge amount of threat at the same time.
A positive note for this card is that it is a Wild resource. Miles's Web Shot, Swing In, and Double Life all require a certain resource to activate , and a Wild will always help with that. You may not always have your Web-Shooters available to pay for these kickers. Gwen is a different case. She doesn't necessarily need Wild resources (she does need a Mental for Web Binding's kicker), but with Captain Stacey on the table she can tuck this away until needed, which is the most frustrating part about Events like these (impactful yet difficult to coordinate).
I rate this card a C: Great effect for a great cost that is too hard to coordinate to pay off.