I think the drop between Rice and Addai is less than Johnson to Bryant. But, if you think that the difference is reversed, then make the trade. It's a fair deal in terms of players, you just have to imagine what your starting lineup will be like. It wouldn't be a dumb move, especially if Rice turns it around. Sorry if that's wishy-washy. I just think it's that close.
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