My vote would go to standard Gold 1.67. I have little P&N experience.
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All that is gold does not glitter,
Not all those who wander are lost;
The old that is strong does not wither,
Deep roots are not reached by the frost.
Quasi-Newtonian Propulsion (big ships need more engines, and use more fuel)
Balanced resource costs
Lots of tweaked techs, mostly self-explanatory, such as weakened APBs and PPBs, torpedoes with accuracy bonus, normal-tech planetary shields, useful armor, etc.