I've found the pop caps to be too restrictive but the mods already released too liberal, so I've created a quick mod to double the population caps at each level so the max is now 400. The files rules.xml and help.xml have been modified, all in game text is also modifed to suit.
Things like the Colossus still only give a boost of 50 so their usefulness has effectively decreased.
Download (83KB): http://bcmedia.biz/files/2xPop.zip I'm interested in hearing what people think of this and if it worked or not.
Cheers,
Quboid