I'm talking specifically about turret factories. Once you get close to the barrier 2 and 3 slot turrets in factories are not uncommon. Around the core this can go up to 5 or 6 slots. Now this would be fine, since at this point you should have at least 20-30 slots on your ship. But as soon as you make a few simple calculations you see where the problem is. The damage is not dependent on the slot number. What this means is while a 1-slot turret might have 3000 dps, a 5-slot one only goes up to about 8000. (coaxials about 12,000) Say you fill 30 slots on your ship with these. If you make the 1-slot turrets that's 90,000 omicron., while the 5-slot ones give you 48,000. It becomes obvious that 1-slot turrets are far more powerful and anything else you're just wasting slots.
In my opinion if a turret requires 2 slots it should, by default, get a x2 multiplier, x3 if it's 3 slots, and so on. And then the randomizer. Give players a reason to use larger weapons. Right now it's just not worth it if you want to maximize firepower.