The European version comes with an extra in the Sphere Grid system: the Expert Sphere Grid. This Sphere Grid works the same as the original Sphere Grid, the difference is that it has a completely unique layout. You start with all your characters pretty much in the center. From there, you can steer any character down any path you like. You could turn Rikku into a White Mage, or Auron into a Thief, for example. Next to that, the paths are all interwoven, which means your characters can easily switch paths whenever you chose.
As the name implies, the Advanced Sphere Grid should probably not be used by new players of the game, since it’s not too hard to make the wrong decision and make the game a lot harder than it should be. Note that once you’ve selected which Sphere Grid you want to use at the beginning of the game, you cannot switch to the other one. Another note is that the Advanced Sphere Grid has about fifty nodes less available for activation, which means you can’t get stats as high as you could with the original Sphere Grid. So if you’re intending on getting the highest stats possible, choose the original Sphere Grid instead.
Other additions to the Final Fantasy X Sphere Grid found in the the International / European edition are a few new abilities. These abilities are:
Final Fantasy X’s Sphere Grid system may be the most versatile leveling system in the history of Final Fantasy. It allows the characters to learn each others abilities, where former Final Fantasy games had their characters stuck in a specific class, with their attributes increasing only by a pre-set formula and sometimes items or weapons. It also is a great tool for the die-hard Final Fantasy fans and those who want to have total control over their character’s stats to get the most out of them as possible. With FFX’s Sphere Grid, any character can become as good (or bad) as any other character, and the way your character develops is completely in your own hands.