eh, I wouldn't totally hang my hat on achievements versus Denver's defense last year.
Their defense was straight-up horrific - witness:
29th in yards allowed per game (374.6)
26th in pass yards allowed per game (226.5)
27th in rush yards allowed per game (146.1)
and even though buffalo did very well that day, putting up 30 points, it's only 2 more than denver allowed on average.
and FWIW, Denver was 4-4 at home last year, which doesn't exactly scream "extremely hard to win at".
Hell, Oakland blew Denver out IN Denver.