I don't have an unlimited policy, and honestly it's for the best as I would likely abuse it.
I'm in North America. I get 3 weeks. I take 3 weeks.
Edit for clarification: 3 weeks of paid. Unlimited if conditions require it (mental leave, sick leave, etc). I generally use 10 of my 15 days to extend 3-day weekends (if we get the Friday off for a bank holiday, I take the Monday as well). I save the other 5 for half days to do whatever.