I believe the game is A.- critical
Any time you can win a game in New England ( considered a top 5 NFL team) the confidence factor can be huge.
If the Bills have any weaknesses, the Patriots will exploit them.
If the Patriots can not take advantage of the weaknesses, then perhaps they really are not weaknesses at all.
Lets face it guys, if you beat the Patriots on the road, in front of a national audience, you can beat any team.