I'd rather stick with Ion Cannon over Flechette Cannon for 1 more point. There are builds that can feed off removing stress, where as, there are no builds that feed off being ioned.
I was considering a Rebel build that used two Blues with Ion Cannons, a Gold with Ion Turret and R3A2, and Roark with Ion Turret and Nien. The list might work better with a Flechette-equipped Blue replacing the Y-Wing, which would free up a point for Roark to take Tactician instead of Nien.

