There are basically 3 things munitions currently do. They may do direct damage, splash damage, and inflict a state effect. The original munitions (proton torpedoes, concussion missiles, cluster missiles) just did straight damage. At the time, this was fine but now protons and concussions don't seem like they do enough for their cost, especially given the other options now available. Most of the rest either have unique effects or are otherwise well costed.
The problem is that these original munitions set the bar for future munitions. That said, FFG has shown that they are more than capable of making a bad card good by changing something in the environment a la munitions failsafe. Here are some ideas of mine:
Heavy Bomber (Title), 0 points - When equipping two or more (missile) or (torpedo) upgrades, reduce the cost of those upgrades by 1.
Improved Targeting System (Modification), 1-2 points - When attacking with a secondary weapon that instructs you to spend a target lock, you may reroll some or all of your dice.
Multi Target Tracking System (Modification), 1-2 points - At the start of the combat phase, you may spend a target lock to acquire a target lock.
The idea behind the title is to make munitions cheaper for a few dedicated platforms, particularly the TIE bomber but also the Y and B. The two modifications get around some of the main downsides of munitions. The first 'giving back' the target lock but only the the attack itself, while the second makes setting up a target lock easier. Since the relock happens at the start of the combat phase, the opponent can still react to it, unlike Deadeye. Also, since both of these are modifications, they cannot be stacked on any current munitions platform or combine with Munitions Failsafe.