Like NE -5 over BUF and GB -7.5 over DET?

Proline pays you 2.00, William Hill pays you 3.82.  $20 down wins $40 or 76.40.  Win more now with William Hill.

Like Dallas -3.5 and Pittsburgh -3 ?

Proline pays you 2 to 1, William Hill pays you 4 to 1.  Lay $20 and win $40 or $80.   Why would you leave that money on the table week after week?  Win more every week with William Hill.

Like GB over BUF, NE over MIA ?

With the spreads, Proline pays 2.00 William Hill pays 3.73, plus the GB is only -4, Proline has them at -6.  Get an extra point for NE as well.  Higher payout and less points to cover with William Hill.  $20 down wins $40 or $74.60.  The choice should be clear.