I used a pre-production SHIELD in a controlled environment at NVIDIA and I watched 4K video clips off of YouTube, UltraFlix and directly off of USB-attached storage. It looked and sounded great. 4K video services are available from YouTube, Kodi, UltraFlix, and Pluto TV and soon from Amazon.
http://www.forbes.com/sites/patrickmoorhead/2...-streamer/
Nice! Again, ULTRAFLIX mentioned along side the giants of entrertainment and tech.