First, the Roku was a POS in my opinion. There are an EXTREMELY limited number of codecs it will work with. I finally got fed up with it and bought a Western Digital Live and it is light years ahead of the Roku box. I have not found a video format yet that the WD box won't play... it will even mount and play iso images.
Secondly, broadband companies (read AT&T, Comcast) WILL have the last word on this. If streaming video starts cutting too deep, they will gladly retrieve their fees by jacking you on pay-per-bit usage.
Yes. Comcast is at war with Netflix. They will cap and throttle your service for streaming and downloading what they consider too much.
I have fios with 75mb, get 85mb. I could download 8TB a day
and they could care less. I have downloaded several TB’s recently. As long as I pay my bill all is good.