[paulk]

I guess we''ve been lucky to have pretty steady breezes and a well-cut/forgiving jib, enabling us to not mess a lot with the leads.
We do adjust them when we switch to a smaller jib, but not having roller-furling means (hopefully) thinking ahead far enough to change headsails before it gets too exciting forward. Performance is improved by having properly set sails, but everything is relative. On a Bristol 32, it might be difficult to measure the difference that moving the lead a foot either way would make.