How to Use Ion Weapons
They are excellent support weapons with anything but phaser and graviton weapons, though they have less impact with blasters. Even so, they certainly do increase the reliability in finishing off enemy ships. They do multiple more damage to certain components and use a different component hit table than normal weapons. That hit table makes ion hits more likely to disable a ship than other weapon hits. Combined with the ability to temporarily disable components even with shields (possibly doing hundreds of shield damage worth if disabling a charged shield) and armor up, supplementing even blasters with ion weapons is a good choice.
Even better than adding an ion to your ship of choice, is supplementing a fleet with some ships more focused on ion weaponry and some boarding pods with a 1 to 4-8 ratio depending on ship classes of choice, primary weapon, and the race. These specialized ships increase your fleet’s capabilities- by focusing them together, you can quickly disable choice hard targets while diverting your fleet’s firepower elsewhere. Their low DPS potential tags them as lower-priority targets, which makes them ideal for all-out support designs or for a cheaper, minimalist supplementary role.
In the measure of getting the most bang for the buck in a large, pitched battle where you’re squeezing DPS, ions still make themselves valuable by making completely disabled ships more commonplace. Such disabled ships, tactically speaking, are dead ships, sparing your fleet having to do hundreds of damage to finish off a ship that would otherwise keep taking a beating until its hull bursts before it stops moving. In this, the aforementioned specialized ships perform better as well, as they’re more likely to make derelicts than piecemeal additional ion to the fleet’s standard ship design. This, I think, puts ion on par with anything it supports, if the right ratio is hit. Too little ion won’t make derelicts and too much doesn’t take advantage of the ion’s strengths.
On the other hand, I’ve used ion weapons as a primary weapon in hard games to cripple entire fleets, allowing me to capture them at my leisure. The Teekan Ion Bomb is particularly potent at this, and even at the early/mid-game tech tier, it overwhelms even the most advanced ion defenses. While they are viable in a single battle (on par with most other weapons by quickly disabling ships), they are terribly slow at finishing enemies since their low DPS is only multiplied against certain components- very notably not including the hull- and much of their damage against those components is nearly entirely mitigated by armor (and doing pretty much no damage to armored hulls). This makes them a poor offensive choice in most situations, strategically speaking, and can only be afforded as a defensive choice if you can predict where the enemy will focus on. They are viable in a battle for a major colony, where they can afford to stay in one place for a long while. In the hard game, capturing entire fleets of ships has a lot of value- especially if concerned about an enemy with restored ancient ships.
With ion as a primary weapon, nothing does well with it except boarding pods. If you’re going to destroy ships, you’d be better off just using conventional weapons as a primary weapon.