For true solo I don't think this card would ever find its way into a deck of mine, BUT for multiplayer games it's great - especially when paired with a leadership deck.
Even when it only activates once or twice a game, it's so cheap that it doesn't hurt to play. It also makes for a nice target for some of the treacheries that force you to discard support cards. The only caveat is, that you need enough targets for it, so be ready to swap it out for minion-scarce scenarios.
This has a nice synergy with Global Logistics, which lets you check the encounter deck before bringing Gambit into play.
Effectiveness aside, it's just good fun when you get to steal Universal Weapon :)
If you can sustain 1 damage per turn, which shouldn't be too much of an issue when playing Protection, Rogue can turn into an absolute goddess on the battlefield. Very few allies have instant access to 3-4 stats right off the bat. She has that! Most heroes easily have 2 THW/ATK, and getting hit by 1 damage for 2 extra stats on Rogue is definitely worth it. Grabbing Protective Training and Danger Room, and/or Med Teams provides a flexible 3-4 thwart or attack from her round after round, which is good enough to build around. One of the absolute best allies not just in Protection, but every other aspect!
This card is extremely powerful after I have tested them in my ally swarm decks. Especially in solo :) Multiplayer may need some coordination to build decks with more diverse traits.
In Solo:
I used to have difficulties ending the game with some ally leadership decks, and had to rely on Lead from the Front. But now running 3 copies of this is immensely powerful!
Some symergystic allies that I really like because they give many traits:
Black Panther - BP can also store one of these to use in the late game, powerful way to directly kill any villain from stage 2 to 3 because 2 copies + allies and hero attacking easily deal 25+ damage!
It works in so many decks, just need to choose the allies carefully. I like this in Captain Marvel because her Soldier trait is rare and can gain Aerial. Doctor Strange also has 3 traits (Aerial with Cloak of Levitation). Ironheart too (with Version and Aerial). Phoenix (with Restrained and Mind Control can add even more with Controlled + the minion's traits). Extremely game-changing card that makes Leadership even more powerful!
These are great.
The damage is not an attack, so you can use them when stunned and they do not trigger things that happen on attack such as retaliate.
These are great for pinging off a tough status card or making sure you do exactly the amount of damage you need to an enemy.
Three of these out means in tiny form you are doing 3.damage and thwarting for 2 before you even play a card.