Yes, we are the best.
It's not just cosmetic btw, each faction plays totally different.
The TR focuses on "we have reserves" style play. Lots of high capacity bullet hose guns with limited recoil, good range, but shit damage. Their shit is fast, light, and poorly armored. But it's cheap and quick to moblize.
The NC focuses on heavy hitters. The guns are short/med range powerhouses. Everythings armored to hell. Slow, powerful, and hits like a truck. Most of the guns have very little ammo, and long reloads, but you'll pretty much drop anything you hit.
The VS is all about mobility. Their air units can stop and turn in midair, and their tanks hover. Their weapons are low damage, but highly accurate with no recoil (they use energy weapons).
Basically, you pick by play style. CoD (TR), Arma/CS (NC), or Tribes (VS).