can anyone help

I've just swapped my 07 575 or an 07 carbon s works stumpjumper. the stumpjumper feels fine but the suspension seems to clunk as its comes back up, as if its bottoming out but at the top rather than compressed if that makes sense.
My 575 had a new RP23 and was super plush, The stumpy has Specialized AFR with Brain.
can anyone give me any feedback on their experiences of the AFR + brain.
its not so much the travel, more about how the shock feels when it returns.
cheers

steve

Have the pivots / bearings been serviced. Mine tend to seize after a year or so if not stripped and cleaned. It starts creaking like mad too. Got an 07 Elite so a Fox Triad rather than the AFR so I can't really compare shocks.