For Netflix, Chrome Cast seems to offer better audio streams when being controlled via a Android tablet vs iPhone or iPads.
Using my 7" Samsung galaxy tablet, my receiver lighted up the HD Audio logo (Dolby Digital +) when streaming some movies. It sounds very nice! The audio/close-captioning selection dialog also shows DD as audio stream.
However, if I use my iPad or iPhone, I only get stereo!! The audio selection screen only shows Stereo!
Suffice to say, this is an interesting find, and I'll be using my Android tablet to control Netflix on ChromeCast from now on! (My other devices, Roku, Sony Blue-ray player, none of them seems to get the HD audio stream). Video quality on the ChromeCast is very good. It starts out a bit crappy, but will automatically change to HD after a short while.
So for me, the ChromeCast has become my best Netflix option:
1. Supports HD Audio stream when applicable!
2. Supports Closed Captioning! I've been wanting this for a while!
3. Great Video Quality