1080p is a resolution, not an image quality.
your digital download probably has a higher bit-rate than the streaming services do. (blu-ray is higher than them both)
one good way to check the compresssion on your image is underwater scenes, the background typically has a nice even fade, on compressed video it tends to turn into a lot of bands instead of a smooth fade.
also why you get a better image off an antenna than cable for your local stations, since cable compresses them to fit more channels.
a little more in-depth article if you care.
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This doesn't apply to those not in the US, but the first month of HBO now is free, just cancel before they bill you at the beginning of the second month.
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HBO has announced that shows will be available for streaming when they start on the east coast, with the possible exception of some live sporting events, which should show up within a few hours.
I'm guessing they'll be in 5.1, so they don't have to deal with 2 different copies at different times.