On a serious note, I'd be curious as to the average PTO taken from your company when compared to a company that had 30 days of PTO for everyone. I would guess the ambiguity of "unlimited" discourages people from pushing the limits, and the bell curve for PTO at your company is <30 days. It seems unfair that "unlimited" is a perk for senior employees who don't have to worry about job security, while "unlimited" is a yoke on marginal employees who keep pushing forward just to appear not to be abusing the invisible line. It sounds like a good benefit until you look under the covered wagon and get a whiff and see that it's not a fair system as it plays off the fear of vulnerable people.