Are you in a ppr league? If so, I say stay put for sure. The Bears can't run, but Forte can get points catchingthe ball. Plus, you are 7-3, so that makes taking a risk like this almost unecessary. What if Tuner is out 3 weeks, then struggles when he comes back?
12 Team League. We start 2 QBs and get .5 PPR, otherwise standard scoring
QBs: Stafford, Fitzpatrick, Collins
RBs: Charles, Mendenhall, Best, Starks, Carter, Karim
WRs: D. Jackson, Marshall, S. Smith, Green,
TE: Hernandez, Cook