Xandre Blackheart, on 08 July 2012 - 11:45 AM, said:
The specifications for the Large Laser-
Heat: 8
Damage: 8
Range: 15 (450m)
Weight: 5 Tons
Critical Slots: 2
And the specifications for the PPC-
Heat: 10
Damage: 10
Range: 18 (540m)
Weight: 7 Tons
Critical Slots: 3
The differences seem negligible at first glance. But on the breakdown you are gaining 2 damage and 90m of range for the cost of 2 heat per shot and 2 tons and a crit space. Considering that 2 tons (and an extra crit space) can be used to even further offset the heat cost (making it 6 heat for 8 damage vs 10 for 10 at the same tonnage) the only consideration becomes range.
I look at it this way:
The PPC takes 50% more crit slots and 40% more tonnage, for only 20% less damage. In other words:
Large laser - 1.6 damage / weapon tonnage, 1 heat / damage
PPC - ~1.4 damage / weapon tonnage, 1 heat / damage
The range difference is negligible, especially since from what I know, energy weapons will not have a clear range cutoff, but a gradual damage dropoff past their maximum range.
Which one you choose is then pretty much determined by what amount of space you have available. I would go with the large lasers first, if I can fit them, so:
5-6 tons : 1 large laser
7-9 tons : 1 PPC
10-13 tons: 2 large lasers
14 tons: 2 PPC
15 tons: 3 large lasers
etc..
Over 15 tons, the large laser is the clear winner, as once you get to 3 PPCs, you could also fit 4 large lasers for 1 less tonnage, but about 10% more overall damage. With that many weapons however, heat becomes a much bigger limiting factor than tonnage or crit slots. After all, 4 large lasers generate 32 heat / cycle, or 30 for the 3 PPCs and that takes quite a lot of heatsinks to get rid of.