By default, the Xbox One displays at 60Hz (FPS), however in the UK and most European countries TVs display at 50Hz (FPS).  This isn't always a problem, but in fast action sequences the faster refresh of the console can cause what's known as juddering. 

Resolving this currently requires a bit of fancy footwork within the settings of the Xbox One.

1.  In the Console Settings, go into the Display Settings and have the Xbox One automatically detect the TV's capabilities.

2.   When the list of resolutions appears, manually select 720p then reject that setting by answering "No" on the resulting pop-up.

This forces the console into a hidden 50Hz mode -- one that the console should automatically use when the HDMI input is activated.

http://www.expertreviews.co.uk/games/1304002/how-to-fix-xbox-one-tv-integration-picture-judder-problems

How do you mean?

I don't live in the UK/Europe, so I can't atest to the accuracy of it. 

If you don't see any judder watching TV (live or on-demand streams from UK/European sources - Not Netflix or Hulu, etc) then don't adjust your console.  I'll have to check with Reddit to see how this converstion is going.  Also remind myself to source both the Reddit conversation as well as the original article.

EDIT:  One report does confirm it works.  At least it minimizes it.

Also reported by HDTV test
http://www.hdtvtest.co.uk/news/50hz-fix-201311263472.htm

Here are the precise instructions. First, set your Xbox One to auto-detect HDMI (under Display settings). Then, toggle the resolution from 1080p to 720p (or vice versa), which should trigger a prompt window asking if the screen is displaying correctly, and if you want to keep the new resolution. Select “No” before the 15 seconds is up. This seems to trick the Xbox One into thinking that the TV is not compatible with 60Hz signal, and voila! 50Hz output. Depending on your television set, you may need several attempts to succeed – the good chaps over at CVG have verified that this unofficial fix works too.

Your games will also run in 50hz though.

The problem with this is some games won't allow 50hz players to connect to 60hz hosted games and vice versa. I think it was either forza or PGR I had this issue with. Hopefully that isn't an issue anymore.

Nice.

From what I've read the Xbone is missing (or omitted) key features the 360 had! It really does seem like it was rushed out to not give the PS4 a head start.

http://www.eurogamer.net/articles/2013-12-03-frustrated-xbox-one-players-suggest-missing-system-features

Top Xbox One feature requests
Xbox Guide functionality to return
Friends as a tab on the home screen
Notifications when friends come online, you receive a friend request
Hard drive management screen
USB support for storage/media
View (and easily rate) recent players
Smarter Kinect phrases ('Play Forza', with disambiguation for duplicates)
Party chat to be simplified, on by default in parties
Set game chat to TV, headset (or both)
Controller battery indicator
System-wide controller options (rumble off, layout save)
Avatar store
Voice messages
Background music
Custom backgrounds
Ability to see Xbox One games/achievements on Xbox 360