It may be true for now. But the competitors are not sleeping and they are catching fast to get the quality better each day. I have tried netflix 4k especially HDR with my bandwidth of barely 6-8mbps sustained, I don't see any buffering and quality is, I would say, amazingly crisps. I have been watching our UF 4K movies and used 80 of the 99 movies already so I'm very familiar of our quality. By that, NF 4k and HDR are getting very close and it's native 4k are even better because some of UF movies are not native 4k. Before you know it, there will be another that can achieve lower than 4mbps with matching quality.
Just read about this...it's a very competitive world...the time runs 3x faster. Slower will be left behind inhaling the dust.
http://www.onlinereporter.com/2015/10/19/tveo...er-2-mbps/