Sorry I've been away from the boards for a bit. Real Life always gets in the way.
Gotta weigh in here for my trusty FSA. Of the original four factions, they are the simplest, most straightforward fighting force. Yeah, yeah, the Prussians have their Tesla bizarro weapons, and the Japanese have rockets that set everything on fire, and the British have...well, whatever they have. But you just can't beat the Orlington main guns when it comes to wrecking hulls. Point, and fire. Pretty simple. Plus, that American steel gives them a slight edge in survivability.
I do very much like most of the follow-on factions, but I feel that many of them require a degree of finesse to play properly--especially the Alliance factions.
Just my $0.02.