Okay, so I must admit, much of my current frustration over the pirates is due to the Distant Stars mod which added capital ships and the Vasari starbase to the Pirate's forces. However, this is not, by far, the main problem I currently see with the pirates. Diplomacy's "send pirates on mission" option is game breaking. If they succeed, their forces return to the pirate base and are not included in new raids, causing a build up of forces. Three and a half hours into a multi-player game with a friend, this is what the Pirate Base looked like:
331 Fighter Squadrons
85 Dunov Battlecruisers
18 Pirate Battleships (a pirate-specific capital ship mesh put in by Distant Stars team)
20 Halcyon Carriers
156 Vulkoras Battleships
1 Akkan Battlecruiser
403 Pirate Cutthroats
134 Pirate Reapers
842 Pirate Corsairs
A couple of rogues and pillagers.
I can almost guarantee that the pirates were 80% of the lag in our game, which became so bad we quit, and likely won't resume. Again, capital ships and starbases are a pain, but the real problem is the constant adding up of pirates on a pirate base. IMO, this is something the devs need to fix immediately.