Who did Seattle play on the road?
Cam Newton Won by 5, Deanglo Williams fumbled at the 2 yard line for the game winning TD
Matt Schaub Won by 3 in OT to the worst team in the NFL in 2013
Andrew Luck LOST
Carson Palmer Won by 12
Kellen Clemens Won by 5 in an ugly ugly game against a backup QB
Matt Ryan Won easily but both Julio Jones and Roddy White were both out
Kaepernick LOST
Eli Manning Won easily against a backup O-Line and depleted team
So they were 6-2 and really squeeked out a week 1 win vs Carolina and a joke of a win against 2-14 Houston, and barley beat a bum Kellen Clemens. They very easily could have been 4-4 on the road.
Let's be real here. Peyton Manning calls a lot of audibles at the line, he pretty much does so on every single play and that would be much MUCH harder to do in Seattle than it would in Denver or a neutral site like New York. Giving Seattle 3 points for playing at home should really be 4 or 5 against a passing QB who audibles a lot. The fact that the game is on a neutral site helps Denver because Seattle's homefield advantage is worth more than 3 points, especially to a QB like Manning.