Don't forget that pirate armor is a new secret type that goes beyond very heavy.  It actually makes bombers worthwhile though, as they can survive the flak and deal additional damage to pirate ships.  Nothing survives the ungodly flak burst of pirate defense platforms though.  They cover the whole gravity well. 

Try this: http://datafilehost.com/download-448aad49.html  Just place it in your mods folder then enable it in-game.  Disable after you've tested it out.

If you like it then perhaps we could lobby for the standard pirates to be more like they are in the mod, less stats focussed, but with better abilities and more inclined to attack trade?  If not I can always adjust it more.