I have the same problem, well, the same feature.
Also I have a FFB2, and I think that the "problem" is that the autopilot and trim are "linked" to the FFB, so instead of move the control surfaces, DCS moves the FFB's neutral position. In my opinion, the final result isn't good. I would like disable the FFB for the autopilots and trims, but I don't know how. :(:(
PS: Same to the other airplanes, Su-27, Su-25T, etc.
PS2: Sorry for my bad english.