I think that depends on your legs and how the suit fits. I've got very in-outy legs (tiny knees and ankles, big muscles and big feet) and it can be a tug. I grease my heels as well as ankles for a quick transition.

One extra area that hasn't been mentioned: the neck. The neck of the wetsuit can chafe in a long swim so a quick grease around your neckline will let the suit slide and prevent a Q-Roo hickey.