X is often in the range of 50-60 whereas Pro is often 40-50 but framerate can vary wildly and both machines can hit 60FPS in certain scenes. Cutscenes run rather well at 30FPS locked with higher quality motion blur and DoF. Wouldn't be surprised if cutscenes are higher resolution too.
This is a much bigger difference than I expected after seeing the base PS4 and Pro performance. I've been playing on X and been annoyed with the framerate, can't imagine how I would be reacting to the framerate on Pro. X looks like a 10FPS advantage in many scenes, hitting 60FPS much much more often but still has a lot of drops.
For those here with a Pro, you can force the Pro to output at 1080p to get framerate results similar to Xbox One X in its 4K mode.
Still no word of what resolution X is running at, has anyone pixel counted? Pro is running at 1440p.