> It has to do with allowing you to move. A true custom molded to your butt
> seat holds you locked in one position only, which your body does not like.
> You can't shift your weight around or move joints a bit and such. So you
> cannot stay with it as long. However, for a short period of time, your
> control of the boat would probably be enhanced by the custom seat, if the
> boat fit as well.

just my experience, I used to race bicycles in my twenties and learned abouut dis/comfort in a confined position for hours on end. A lot my ability to be comfortable in a restrained position is by learning to use the postural muscles in a relaxed and dynamic way. In cycling the upper body and lower back help hold a posture,in kayaking it seems that the hip,thigh,and internal (?) torso muscles do that job. So while the seat is custom, the pressure points have all been eliminated allowing for better circulation,(beginning to sound like "how many ngels on the head of a pin stuff") funny thing,at one time track racers used hard plastic "Unicanator" seats because they could slide around easily on the saddle.... a few years ago bike s eat makers came out with "stitching" so that racers wouldn't slide around! so kayak racers are probably as pain tolerant as bike racers, but not this paddler. I'm comfort driven.