I see this being repeated over and over but I can't help but think that it's become a way to discourage giving employees time off from a company's perspective. I've successfully taken 30+ days off in an unlimited vacation environment (not consecutively) and not been reprimanded in any way because I was able to operate responsibly. Before I left for any length of vacation, I made sure that projects were delivered and successfully launched weeks before hand and I created documentation and trained others on continuing work processes (the lack of my presences should not have ANY impact).

"Unlimited vacation" should be a work perk that is attractive. Often times I find that it's the managers who don't believe employees should be given time off or the company decides to just implement unlimited vacation without any process in place to revoke the privilege or guidelines as to what a responsible policy looks like. It's easy to say something doesn't work when there was never any intention or effort to make it work.

Just my 2 cents.