I've got several colleagues considering this. As their children move out of the house and the mortgages get paid off. They've qualified for the pension (collected at 60? 55? I can't remember, it's far enough off that it doesn't affect my planning much here). They're only in their late 40s or early 50s, so if they switch to 60/80% time they'll take a pay cut, we'll have money left to hire more people. We'll retain their knowledge base. They can ride to retirement comfortably with long weekends every week.