Maddox is a quality backup QB. He's a QB capable of taking a team to the playoffs assuming he has a solid defense and running game to supplement him. He needs that defensive help because he is a gambler. He tends to force some throws, which is why he has a 21:23 TD-INT ratio the past 3 years.
I do expect Maddox to be released, but I doubt the Falcons would be in the running for him. In fact, I believe he'll likely head to Miami to where Mike Mularkey is. He was solid in Pittsburgh during their shared years there. He has truly struggled in Ken Whisenhunt's offense thought the past 2 years, just take a look at these numbers:
49% completions, 3 TDs, 6 INTs, 54.7 rating
Maddox would definitely work as a backup. He causes headaches, but he's still probably one of the 10 best backup QBs in the league.
"Vincere scis, Hannibal, victoria uti nescis" -- Maharbal, 216 B.C.E.