No. They're not intended to be any different, except that they don't produce smoke, and they're a bit more 'fantastic.' While Pathfinder Players seem pretty on-board with gunslingers, when we first released ZEITGEIST, 4th edition hadn't made firearms part of the mainstream, so we wanted our guns to be less like those in the real world, to keep from turning off people who don't like 'modern' tech in their games.
But mechnically, it all basically works just like gunpowder. Oh, except that it works underwater.