The International One X and the One X+ have a lot more in common than our US One X did. You'd gain a somewhat faster CPU and maybe 10% better battery life. HTC hasn't used card slots because they're trying to make the phone as thin as possible while maintaining a unibody design. Card slots and removable batteries are very convenient, but require a thicker device or a change away from the sturdy unibody design.
-------------------- Lisa Gade Editor in Chief, MobileTechReview