I watched last night's game on Amazon, and it looked just as good as broadcast via antenna. Perhaps it's my fast internet speeds, but I specifically watched for this reason, and it never dropped off, ONCE it spooled up after about 30 seconds.
Amazon should dump an aircraft carrier of money on the NFL, charge $10-$20 per game you actually want to watch, and then also buy RedZone which can be included for something like $10-month. I'll run to pay for these options, tomorrow.