What I keep coming back to is that Heroic feels really well priced. It's worth about 1/3rd to 1/5th of a reroll, and costs 1/3rd to 1/5th the price of upgrades which plain get you that reroll (X-Wing: no offense, 1/3rd of Elusive) (A-Wing: 1/5th offense, 1/5th defense, 1/5th of Predator+Elusive).
So it's the same effect as other Talents, just scaled down. It's not as big, but it's a lot cheaper.
Exception: Heroic and Finn on a Falcon. A Falcon will roll a blank 3/8ths of the time on it's single green die, Finn can add the 2nd blank blank, and then reroll both dice. That's kinda solid, and a decent number of Falcons probably have Finn anyhow.
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Personally, I find the comparison to Predator or Trick Shot as odd. Heroic is pure random chance (and admittedly slim chance), but it's always on. Predator and Trick Shot require positioning that isn't necessarily reliable on a lot of pilots. Heroic is always there. Doesn't matter what you do, what your opponent does, or how skilled you are at taking advantage.