Worked for a (now defunct) Silicon Valley company that did this. My experience also really turned me off to the whole idea.<p>The problem was that it was not clearly defined across the company how much vacation was too much or too little, and even if you hear one thing when you get hired, a reorg can put you under someone with a totally different viewpoint. Meanwhile, in companies I've worked without unlimited vacation, it's clearly defined how much vacation is too much, because you can't use more than your bucket.<p>My first boss was the one who hired me into the company, and when he called me to present the offer, he told me that as a European he felt people in the US don't take enough time off and he wanted us to do 4-5 weeks a year. At one point mid-summer he told me "I don't think you've taken enough time off, it's slow next week, so go have the week off and take your kid to the pool a lot."<p>That boss left the company, and I got reorged into a team that was pretty much the remnants of a startup that my employer had acquihired. The company was pushing this team to develop and release a particular new product concept ASAP, but giving minimal staffing to do so, so it was constant lowgrade crunch the whole time. The manager (and former founder of that startup) was also still operating in startup-hustle mode and setting the sort of example that while you technically get time off, you'd best not be taking a whole lot.<p>I worked under each boss for a year. Under manager 1 I took 4.5 work weeks off in 12 months. Under manager 2 I took 7 days off in 12 months.<p>Not a lawyer but I imagine that companies don't provide more guidance on _minimum_ vacation time usage, because maybe that could be construed as a bucket, and would put you back under the idea that in certain jurisdictions (California included) vacation accruals are viewed as compensation duly earned by the employee but not paid out yet. Avoiding having to carry that as a liability on your books and pay out when people separate, as I understand it, is the primary purpose behind unlimited vacation policies in the first place.