I apologize if I'm late to the party and this has already been resolved within the thread...I basically read a few pages and fell upon the discussion of 'pocket presence vs. mobility'. I think they're 100% intertwined and just because a player is comfortable outside the pocket doesn't mean he's helping his team by being out there. The ability to stay in the pocket, to move around the pressure, and still deliver a strike, is key in any NFL offense. Tom Brady's average pass attempt this season has gone for 8.6 yards, Ben's for 8.0. So an inability to stay in the pocket and deliver a strike when there's pressure on is taking yards away from the offense, and scrambling isn't going to make up for that in most cases. So here's my (very) quick and (very) dirty analysis of 'Brady vs. Ben: mobility'. A mobile quarterback is someone who 1) feels pressure and can move around, deliver the ball despite the rush; and 2) knows when to pull the ball down and run with it, and also the QB's ability to turn said run into positive yards for the offense (again, knowing that they both deliver 8+ yards an attempt, it isn't necessarily a good think when they tuck and run).
Brady's been sacked 16 times for 101 yards; Ben 35 times for 254 yards. Brady's rushed 24 times for 78 yards, Ben 27 times for 154 yards. If you eliminate sneaks--I couldn't image they'd effect the numbers that much--this is the sum total of times that these two have 'allowed' pressure to get to them, either by getting sacked or running with the ball. I see two things with these numbers: 1) Brady doesn't let the rush get to him as much (40 rushes + sacks vs. 62 for Ben), this allows him to deliver more pass plays which, as noted, is important because of the yardage generated on an average pass; 2) even though Brady doesn't scramble as well, he doesn't allow good pressure to hurt the team as much: Ben has been sacked more than twice as much as Brady, and one would assume that a good number of those have come from an inability to avoid the in-pocket pressure and/or a poor job of scrambling. If you combine the numbers (subtracting the sack yards from the rushing yards), you have a -23 for Brady, and a -100 for Ben; while he 'scrambles' more successfully, his ability to avoid the initial pressure is considerably worse and, in the end, hurts the team more than his scrambling helps.
All that said, this is all moot because to truly compare them you'd have to have them running the same offense against the same defense. I have alot of respect for Ben...after his rookie year I thought he was a flash in the pan, a 'system' QB who let the running game carry him to the SB. But this year he's truly emerged as a threat all his own, and he's still young. At the same time, comparing him to Brady seems ridiculous.