FC2 was a longer game, but for the wrong reasons lol.
The constant and long walking, running, and driving to go back and forth between many same locations, plus missions that are mostly the same thing over and over. Add to that no fast travel except 4 bus stops far away from each other. And the constant respawning enemies that chase you in trucks!
Its still one of my favorite games, but FC2 has flaws equal to its great points. FC3 fixes the issues and allows you play at your own pace.