Even going back only to Cunningham, the game was different then. Whereas their overall passing stats are somewhat similar, Cunningham had 5 seasons with stats that put him in the top 10 in most categories, and once lead the league in QB rating. Vick has not found his way to the top 10 except an isolated instance or two. The game has gotten easier for throwers, to the point that even Favre's records are not likely to last long even if Manning doesn't break them in the next couple seasons or three. (The TD record could be Mannings this season.)