That's about right, Aub. They also cost half as much, and I will likely be adjusting the to-hit mods and size (probably to 10kt) more for 1.6.
The idea is that sometimes you want an important ship, base, or planet to protect only itself. The short range in this case is something you want, because it prevents non-essential targets from drawing your defenses away. Even with the +70 PDC, fighters in Proportions will often be missed.
PvK
quote:
Originally posted by Aub:
PvK,
there is something I'm missing about Self-Defense cannons. It looks like they require the same tech as Point-Defense cannons, cost only marginally less (e.g. 15 vs 20 tons) and are almost useless against fighters (at least in multiplayer). And if that's not enough, they lack the 70% bonus PD cannons have.
What is the reason to install them then? It looks like I'm better off with the original point-defense cannons!
Now what did I miss? 
Aub