G-Sync matches the refresh rate to the fps, that's why it's smoother even at frame drops. I watched a review from JayZTwoCents (or however his channel name is 'spelt') on YouTube and he couldn't believe he hadn't moved to it before. His rig is GTX 780 three-way SLI'd though so his can definitely handle it (3 of them I think he actually tests). Just read and look at reviews, they should give you a better grasp, providing your rig can keep up well too.