I ask because I've heard that "unlimited vacation" actually results in LESS vacation being taken because employees are afraid to be seen as the one abusing the system (even though taking 4+ week/year should be norm).
Somewhat related, I loathe the trend of grouping sick and vacation time into a single bucket (for those in the EU, in the US, if you're sick you have to burn leave, the concept of "you're sick, stay home" doesn't really exist).