It's not a BS trend at all, maybe phrased incorrectly using the term "unlimited", but it's actually a great benefit if you're capable of understanding that there are socially acceptable limits to these "no policy" benefits and that timing long vacations takes planning around your work load. Getting ready to ship a big feature or tool? Maybe once it's been in prod for a week it's a good time to take off for a couple weeks before you get tossed into the next big thing. Let the PM's know you're going to be out so they can schedule around your absence and it's not going to be a big deal. Obviously, the company has expectations about your availability, but also respects your need for a work-life balance. So, you have to be the kind of person who is aware of whats going on around them, what your needs are and what the company's needs are, and finding a balance. "No vacation policy" is not an all-you-can-eat buffet.