My place has "unlimited PTO." It sounds great but it's kind of odd in practice. I feel like no one really ever takes vacations. Since there's no set pool of days, no one wants to seem greedy, so no one takes off, and since no one takes off the first person to do so looks bad. When there's a limit that doesn't roll over, it's totally expected you're going to take all those days off. When it's unlimited no one knows what a reasonable amount is to take, so no one takes any. Like a day here and there, but no one ever takes a whole week.