My current employer has an unlimited vacation policy. Really it's just a joke because it's a way for them to write off a crude vacation as an expense from their books. Since vacation is no longer than accrued earned benefit now when I quit I don't get paid out any outstanding vacation because there is none. In reality when you have accrued vacation that has a maximum limit you will end up taking your vacation because it's a tangible thing and if you don't take it then you will be leaving money on the table so to speak. Going to an unlimited vacation policy people tend to take less overall vacation because they don't have a number sitting in front of them that says how much they can carry over a year to year and how much they'll lose if they don't take it.

Since vacation still needs to be approved by your manager or HR I'm shocked more places don't go to unlimited vacation. My employer is pretty good with vacation as long as you don't take unreasonably long stretches. If you try to take more than 3 weeks at one time they do end up questioning you about it because that seems like a abnormally long period. Overall I've taken eight weeks throughout the year and never been questioned with it. I imagine not all employers are happy to authorize that much even though the policy is technically unlimited.