Quoting Will the Great,
Giving it the same fire rate as the Kortul's pulse beams is way way too much, too. It'd be fun, sure, but it wouldn't make for an interesting game.
Now, a dedicated capital with nothing but that superlaser and with a cooldown (30 seconds, say), THAT would be a good idea.
Well, the reason for that idea is that I'd want the Vasari battleship and the Kol to be balanced. I suppose that the Vasari Kortul could produce less damage.
Hmm, would the equation be something like,
Damage_Kol * ShotFrequency_Kol = Damage_Kortul * ShotFrequency_Kortul ???
Personally I don't see anything wrong with instant capital ship killers (see my mod thread) , but the important thing is to give it some negative effect (such as Damage/sec being lower then others). If you make the Kol instant kill, the Kol would definately win even if the damge/ sec were the same, that is if it is only a Kol vs Kortul. Since the main weapons practically auto fire the vasari player could first send in one frigate, and make it fire on it and make the kol into cannon fodder, then send in the Kortul for the kill. If the Kortul can't defeat it in the time (if damage/sec is the same it techniacally almost should), then retreat it and repeat.
Also note that if you make it so that your eqoution is High*low = Low*high then they will be specialised against different things the Kol will be good at taking out single targets such as starbasses, lvl 10 capitalships and maybe planets? while the Kortul would be good against masses of weaker units and maybe tougher ships (this is more a mather of damage/sec then shotfrequency alone).
Well that was my 2 cents on the mather hope it helped