@ Goumindong: Mortars are cheap, low flux use, and pile on a little more damage to unshielded stuff after Heavy Blasters, Salamanders, and Mines do bad things. I only use Light Mortars if Doom does not have Hardened Subsystems. If I squeeze Hardened Subsystems in, then the universals are empty (or the medium missiles are empty and universals have single Salamanders). Doom (as I configure it) relies solely on Heavy Blasters and (primarily) mines to kill stuff, plus occasional Salamander to distract AI a bit. Mortars are set to alternating. I stay far away from enemies (well beyond 700 range) until the enemy cannot fight back. At that point, it does not matter too much what small guns, if any, are used.
However, if I am poor and do not have elite weapons, just common junk, then I use Pulse Lasers in mediums and Light Autocannons (or more Salamanders) in the universals.
I just dont buy that the light needler is particularly underpowered just because its not the go to kinetic to fit on every ship
Light Needler is not really underpowered, just overpriced and almost totally overshadowed by Railgun due to doing much of the same job for 2 less OP. Even with I try to use Light Needler for burst shenanigans, it is not working miracles that puts "simply pounding away with Railguns until enemy is vulnerable then burst with other weapons to finish the job" to shame.
While the heavy needler is a bit better positioned in terms of range its a lot worse positioned in terms of OP (and the all important armor damage!) compared to the arbalest which is almost directly analagous to the railgun; you can fit two arbalests for 16 OP and fire 300 DPS for 240 flux out of 2 arbalests with 150 pen.
I meant to compare Heavy Needler to Heavy Autocannon, since both have 800 range and close DPS and flux use. Sometimes, I take two Heavy Needlers over three Heavy Autocannons on Eagle. Heavy Needler would a complete upgrade over Heavy Autocannon if OP cost was not a factor.
For Light Needler and Railgun, Light Needler only has slightly better flux efficiency and possible burst action as advantages over Railgun. In other words, Light Needler is a sidegrade to Railgun (if their OP costs match), not upgrade like Heavy Needler over Heavy Autocannon. I do not think burst action is worth 2 OP and some worse stats over Railgun. If I am undergunning a medium mount, I will probably take Arbalest over Light Needler, but maybe not over Railgun.