[Jong1]

It's only red button for sport. And even then the sports appear in a special UHD section of the TV guide, so you can set the UHD shows to record too.

There are UHD movies, free with Sky Cinema and to buy through Sky Store, which are downloaded. They can be watched when 'enough' of a buffer has been downloaded. For me with 200Mb/s Virgin broadband this is after about 10 secs, typically. I have never experienced 'buffering' when watching content downloading from Sky - Virgin broadband does a great job! There are UHD Boxsets that work the same way.

There have been only very few new shows so far, where UHD is available simultaneously with first broadcast. Sky seem to be "busking" that a bit at the moment. For The Young Pope they are adding the UHD episodes to a box set just before the show airs, so people can choose to download the UHD version instead of watching on Sky Atlantic. The Blacklist seems to be done in a slightly different way. But Sky have said they intend a better way, which may mean the same red button style system or a special UHD Channel. We don't know yet. Rumour is maybe around the end of the year, but that's pure speculation!