I can't speak to the change to Jim Bates defense, Jene knows more about that, but based on what you replied here is what I see:
CB1=27.12/gm
CB16=19.81/gm
CB32=15.17/gm
CB16 scores roughly 73% of the pts that CB1 does.
CB32 scores roughly 56% of the pts that CB1 does.
In zealots (non ppr) last year through 13 weeks, Chad Johnson was the #1 WR with 159 pts. Lee Evans was #16 with 119.4. Isaac Bruce was #32 with 90.4.
Lee Evans scored about 75% of the pts of CJ. Isaac Bruce scored about 57% of the pts of CJ.
So, it looks to me that CBs in your league are about as important as WRs are in zealots.
Once you crunch this data, people who vote in this thread should ask themselves "Would I trade away the 1.12 of a 16 team league for a top WR who may be getting old but is a #1 overall at his position (a guy like holt, TO, Harrison, or DJax comes to mind).
Its tough to say, but Champ has put together back-to-back good seasons fantasy wise.
I am inclined to do the trade for champ, but I would like to see you throw in your 2nd and one of your QBs or TEs and have him send back a QB who is an upgrade.