I added Luck a couple of weeks ago to start for Peyton this week, but I don't have the other options available that you have. This is pretty tough, because you have so many decent options to choose from.
Although I'm starting the Browns as my defense this week (there's almost nothing available this week!), they are the 4th best defense for QB's, so Luck could be in for a good rebound game. Fitz and Freeman have the other really good matchups (TEN is 2nd and NO is 6th best for QBs). Luck has had one bad game, Fitz has had two bad ones in a row, and Freeman has the hotter hand, and will probably have to throw a lot. Plus, BUF may continue to run a lot, limiting Fitz' chances. Cutler and Romo are too risky for my tastes.
So where does this lead? I think I'd rank them Luck, Fitz, Freeman, Romo, and Cutler. Hope this helps!
Help with mine?viewtopic.php?f=19&t=526286