I've always been a Romo fan, so I have a little bias to deal with. On the one hand you have Dak who is still playing the hottest rookie quarterback hand the NFL has ever seen 6 games into the season, and on the other hand you have a franchise pro-bowl quarterback who has 10 years of NFL experience, playoff victory experience, and is one of the most prolific passers in the league. Also your rookie quarterback may lose steam, get figured out by NFL defenses, or melt under the bright lights of division races and playoff pressure, versus a quarterback who has historically had mixed results in his most important games, likely only has a few good years left, and may get re-injured again at any moment. Personally I think you have to do what the 2001 New England Patriots did in the same situation with Tom Brady/Drew Bledsoe. Let your newcomer keep his starting spot (he's earned it, plus you'll lose your team if Romo struggles), and keep Romo as a pricey backup.