There isn't a defined number of days that you're "entitled" to. Not that the entitlement is always taken or that people always feel comfortable taking it, but at least it's there. (And, personally, I've essentially always taken my earned vacation.)

I don't necessarily have a problem with unlimited/unmetered vacation. It means you don't get a payout if you leave a company but I don't really have a problem with that. However, I do think it puts the onus on management to set clear and reasonable expectations around vacation--which hopefully are what I would consider reasonable.

If I were to entertain an offer with an unlimited vacation company, I would expect HR or the hiring manager to be able to answer the question: "Is 4-6 weeks of vacation considered reasonable?"

ADDED: I'm not complaining about downvotes but I'm genuinely curious what someone finds objectionable or controversial about this comment.

Not parent but unlimited vacation policy is often criticised as a way to bully people into taking even less vacation. Since you can’t know how much is “okay” you end up in a guilt trip if you take more than some colleague.

Hence my point that there needs to be clear top-down setting of expectations. If you have company management that looks on "unlimited" vacation as a way to avoid having to pay out accrued vacation if an employee leaves combined with a way to grudgingly allow a day off here and there when it's convenient for the company... That's going to be a very bad fit with an employee who sees it as an opportunity to take a couple months off every year.