Regarding auto pilots, I use an Autohelm ST4000. If I installed it today, I'd like to install the drive further forward on the tiller. With the extra lever arm, the unit won't have to work so hard. It will sacrifice some speed. Can you imagine how hard it would be to steer a J/30 with an 18" tiller?
Regarding center of efforts in sails, if everything else stays constant, bigger jibs/genoas move the overall center of effort aft, increasing weather helm.
