This is a lot more of a profound decision than you guys think it is and not because of who is right and who is wrong. Either QB could have success and there is merit to both QBs running the team.
You can't ignore the teams viewpoint in whether to supplant Dak with Romo. The team could easily be divided on this issue the same way that the board here is divided. That could be bad. You also don't want to shake the rookie or piss him off and break the streak of what you have going.
I personally would delay Romo's return for a week or two and see if Dak's play helps you make the call. Romo gets healthier and gets the rust off before he goes back in. Of Dak falters against Green Bay or Philly then you have a natural reason to bring Romo back in.
If Dak wins against Green Bay and Philly, I really don't know how you pull him out at that point. He would be 6 and 1 having beaten 3 relatively strong teams and 6 in a row.
Granted part of the reason we are winning is not Dak and Romo might be able to do even more. But the flip side is that with Romo he is likely to piss a game off with unnecessary risks. The one thing that has bothered me about Romo is his tendency to go for a 30 yard pass on 3rd and 3. It's great if you hit it, but it is a drive ender if he misses it. Dak would get the 3 and move the chains. Both have their place but moving the chains is what wins games and scored points.