People need to stop comparing how the Pats did vs. the Bills' offense with how the Dolphins did vs. the Bills' offense or even looking how the Bills' offense did on Sunday vs. the prior two weeks. The Dolphins faced Trent Edwards and the Pats faced Ryan Fitzpatrick. If a team shutdown the Pats' offense with Brian Hoyer as QB would it be the same as shutting it down with Brady at QB? That is an extreme, but the point is the same. Different QBs can change the effectiveness of an offense.
Fitzpatrick is a better QB than Edwards (hence why Edwards is a Jaguar right now). Edwards' endless checkdowns allows teams to put pressure on him especially with the Bills' porous o-line. Fitzpatrick is a more decisive QB and has more of a vertical threat. He is better for at least Lee Evans who is a speedy WR who can get down field and he makes it harder to put pressure on him because he does make quicker throws.
Fitzpatrick is not a great QB, but he is better and different enough from Edwards to make the Bills' offense a lot different and probably a lot better. The Bills offense with Fitzpatrick isn't going to rival the Pats, but I bet it will be far better than it was under Edwards.