I recently started watching this series, and I've never seen the Japanese version. How much of the footage is Japanese? Is it everything that has the Kamen Riders in their costumes?
Is there a site that compares the Japanese version to the American version?
I'm not sure how much of the footage is from Kamen Rider Ryuki, but if you find footage where the framerate doesn't look very smooth and the quality looks sharper, it's definitely the Ryuki footage. Also, pay attention to how the costumes look in both the Japanese and American footage.
You can also usually tell if it's Japanese footage.. there's NO GOD DAMN SHAKY CAM! I don't know why they just don't leave in the Japanese footage because that's always their main appeal. The American action footage is just laughable.