In the Slave 1 set I find two "unique primary weapon" upgrade cards, the Ion and Heavy Laser cannon.
If I purchase either one does it replace my "3" primary weapon, or may I use it or the card's "attack" at my discretion? Even hand weapons in the SW universe have multiple settings, maybe the upgrade is a "stun setting" writ large?
I ask because purchasing an Ion Cannon might make it hard to finish off a marked ship if I can only do 1 damage each turn!