So i was playing and I noticed, the Ion Cannons really seem lame now. They gib 4 every 8 seconds, which really doesn't seem like much at all. I don't remember if they were 1/second or 1 per 2 seconds before, but 4 every 8 seconds feels really lame =/
Here's my idea. Have Ion cannons go back to one shot. Now, give them an ability that says "Gains an Additional Shot for each X Enemy units on planet", which does exactly what it says on the tin (X being experimented with for a sweet spot). This keeps Ion Cannons scary to large fleet forces without feeling like you can't attack with smaller low-cap raiding forces and achieve nothing.
Basically, Ion Cannons before when they were firing streams of projectiles were something you could never afford to attack given that you'd be quickly losing ships as long as you remained on the planet, and attrition would kill your resources before you could clear it reasonably. The new ion cannon is a non-threat to reasonable sized fleetballs, and you can even assault multi-cannon worlds without caring once you have a large fleet. Never mind the current strength of starship only games and lowcap units in general =p