From what I understand and from my own experience, the only thing that the weapon techs do is to either a) increase the amount of damage done eg. laser IV does more damage than laser I

decrease the size and/or cost of the weapon to be placed on the ship.
I don't know whether someone has mentioned this before but GC2 definitely needs more variety of weapons. Some examples:
- Weapons that damage the defense specifically and does not damage the ship. Maybe a "defense depleter" that reduces an enemy defenses by a certain value for a certain X combat turn.
- Weapons that specifically damage other weapons. For example a weapon that reduces the missle attack value by a certain value for a certain number of X combat turns.
Different variety of weapons will make the strategic combat more worthwhile and it will, possibly, eliminate the old problem in GC1 where you just have to out-tech the AI to be strong militarily.
Another suggestion is to show a damage and defense range, instead of a single value. From what I understand when a ship attack, it rolls a value from 0 to their maximum attack value. So for example, a ship with 4 in laser will roll 0 to 4. The same is true for defense.
I suggest each weapon attack or defense value should be a range. In this example, 0 to 4. Why? Because then you can created weapon techs that...say...increase the minimum value or the maximum value. This will give much more strategic depth. So for example, you can have weapons that do one particular damage (say 20 to 20) or one weapon that does (0 to 20)...of course you got to balance cost and space...but I think it would be much better than the single value we have in GC2.
BTW, you may notice that they do this in MOO2. Now I'm not suggesting that Stardock should add MOO2 stuff or Tactical combat or anything like that. However, I really believe that the additions of different weapons will make the current strategic combat more fun in playing and will make designing ships even better.
BTW, I love the game...and these are merely suggestions for future updates or GC3!
What kind of weapons do you think should be included in the game?