The continuing challenge with space-based missile weapons has to do with speed. Missiles tend to cause damage because they nearly always hit exactly where you fire them due to their guidance systems.
The Stinger missile is very expensive to construct but does twice as much damage as any other weapon class of a similar generation.
The Stinger missile project has been a very controversal project within the political community. The idea of arming ships with high-yield warheads that could potentially be used against cities has created a great deal of resistance to the entire missile development project.
One of the areas we have worked towards is to create warheads that are conventional in nature (i.e., non-nuclear, non-fusion based warheads). The Stinger, like all missile based systems, is very good against ships without defense. But missiles are also relatively cheap to defend against. They can be blocked with chaff or interfered with through electronic counter measures (ECM). They can also be literally shot down with point defenses.
So while the advantage of missiles is that they cause more damage than other weapons, the technologies to counter them tend to be cheap. However, against enemies with little defense against missiles, the Stinger and we suspect its descendants will be quite lethal.