[StarShadow]

I'd go with faster, extra defense and extra abilities.

Example:

Name := Escort
Short Name := Escort
Description :=
Code := ES
Primary Bitmap Name := Escort
Alternate Bitmap Name := Escort
Vehicle Type := Ship
Tonnage := 150
Cost Minerals := 150
Cost Organics := 0
Cost Radioactives := 0
Engines Per Move := 1
Number of Tech Req := 1
Tech Area Req 1 := Ship Construction
Tech Level Req 1 := 5
Number of Abilities := 5
Ability 1 Type := Combat To Hit Defense Plus
Ability 1 Descr := Small size makes ship 60% harder to hit in combat.
Ability 1 Val 1 := 60
Ability 1 Val 2 := 0
Ability 2 Type := Phased Shield Generation
Ability 2 Descr := Advanced hull design incorporates a phased energy matix.
Ability 2 Val 1 := 100
Ability 2 Val 2 := 0
Ability 3 Type := Combat To Hit Offense Plus
Ability 3 Descr := Advanced targeting system increases chance of hitting enemies.
Ability 3 Val 1 := 25
Ability 3 Val 2 := 0
Ability 4 Type := Emissive Armor
Ability 4 Descr := Advanced hull design is resistant to damage.
Ability 4 Val 1 := 30
Ability 4 Val 2 := 0
Ability 5 Type := Extra Movement Generation
Ability 5 Descr := Lightweight composites enable faster movement.
Ability 5 Val 1 := 7
Ability 5 Val 2 := 0
Requirement Must Have Bridge := True
Requirement Can Have Aux Con := True
Requirement Min Life Support := 1
Requirement Min Crew Quarters := 1
Requirement Uses Engines := True
Requirement Max Engines := 3
Requirement Pct Fighter Bays := 0
Requirement Pct Colony Mods := 0
Requirement Pct Cargo := 0

Unless I've misunderstood how to apply some/all of these abilities, this would result in an 'Advanced Escort' with a 60% defense bonus, 100 phased shields, 25% attack bonus, immune to weapons doing less than 30 damage, and a movement of 10 using (a max of) 3 engines (assuming ion engines).

Probably over-powered but just an example after all.