For both 0.8 and 0.81, I've been playing a salvage build pirate. And with the latest nerf to leadership maintainance cost reduction, d-mods have risen greatly in relative strength. The salvage playstyle is quite strong, but just requires a different mind set when playing.
First, don't buy ships. Kill people for their ships. Need a super rare ship? You don't need to fly around markets. Go to TT and kill their fleets until you get what you want. Money is only for supplies and crew, and restoring your flagship if you want.
Second, D-mods are amazing. I've begun farming certain fleets to recover ships, in attempts to get specific d-mods on specific ships. Honestly, the supply cost reduction of some d-mods FAR outway its costs for certain ships. For example, I do not fly cargo ships that do not have d-mods (a shipping fleet costing 0.3 supply a day? Yes please. Freighter costing <1 supply per month? Yes please). I do not fly high-maintainance ships without d-mods. Here's my tier of d-mods.
Tier 1: You want these. Negative effects can be ignored.
Compromised Armor
Compromised Hull
Structural Damage
The more the ship relies on shields or maneuverbility, the less relevant the above d-mods are. These d-mods are so good that I prefer hyperion, tempest, afflictor with these d-mods than without. These d-mods are even acceptable on many cruisers flown by the AI, as long as the cruisers are either Mora or dominators.
Tier 2: 10-20% OP to compensate for these d-mods.
Faulty Power Grid - general annoyance on ships. Can be compensated for by playing around with your capacitor and vent loadout.
Unreliable Subsystems - kills SO ships. Otherwise fine.
Glitched Sensor Array - Annoying to have, but can be compensated for through hullmods. think of it as 10-20% OP loss.
Damaged Flight Deck - Annoying, but can be ignored on most carriers. Just need to use fighters that die less (daggers, longbows, etc)
When determining loadouts for ships in the above, do not be afraid to underequip a weapon slot (small weapon in medium turret) or to not equip a weapon at all. Not equipping that rear facing PD might be worth the 4 OP it saves, giving you some extra points for making the ship at least strong in a frontal role.
Tier 3: pretty bad, scrap these ships.
Degraded engines - An honest pain in the ass for most ships. While allocating 10-20 OP for a augmented drive field negates this effect, the D-mod still lowers the potential burn speed for your ENTIRE fleet by 1. This is the one d-mod I do not want to see on my tugs.
Phase Coil Instability - <30 second peak performance time on a SO phase ship? No thanks.