If you want to tinker with your ship's power settings with different cores (including Fleet versions), engines, deflectors, shields, consoles, skills, etc., then download my Ship Power Calculator (linked in my signature). The Calc will show you what your power levels will be before you make any purchases.
When XP earnings during a Double-XP Weekend still feel like I'm underperforming,
there's something terribly wrong with the reward system...
You can find/contact me in game as @PatricianVetinari. RIP Terry Pratchett. Original Join Date: Feb 2010.