alt+control+shift+s brings up the streaming menu while streaming netflix. From there you can manually select the highest bitrate, so your stream stays in HD -

alt+control+shift+s brings up the streaming menu while streaming netflix. From there you can manually select the highest bitrate, so your stream stays in HD - you can also use a different CDN which may have a better cache. Also, could your ISP be throttling your netflix connections? mine (AT&T) does this regularly, so i use my VPN connection when i stream netflix and have no more issues. Just thought I would share what worked for me