I think I'd be happiest with 4-12 weeks of "vacation" per year, but in a way which is minimally disruptive to the company. This isn't necessarily part of the "unlimited" aspect of vacation, but can be related.
1) Flexibility to take short vacations whenever there isn't anything to be done at work. This doesn't often happen in an early startup, but it's not too uncommon in a larger company to have a day or two where there is some external block. If you can work from home or otherwise be on email, there's no particular reason to just sit in the office that day.
2) I personally count most conferences, even when speaking, as vacation -- even if the company is paying expenses. Essentially, if it's something I'd go to myself, I'm happy to be going on the company dime, and it serves a lot of the purpose of vacation.
3) When long distance travel is involved, I'd usually strongly prefer to take a day or two before/after as vacation, particularly if it's somewhere interesting (which, for me, could be a lot of places). Sometimes this is at employee expense, but there are a lot of cases in consulting where flying someone back for the weekend is more expensive than paying for a weekend hotel. "Be reasonable" seems like the best policy for the expense part, but if you don't have kids or another reason to go home on the weekend, why not spend the weekend in Berlin or LA or something? (relatedly, I'm willing to use my frequent flyer miles to help the company on travel when it's expensive, in exchange for getting to use preferred carriers when the price isn't unreasonable.)
4) In ops, it's often useful to have people show up on weekends (for a consumer service, sure, you can push updates on Tuesday at 9am, but for enterprise stuff, weekend upgrades are actually pretty common); offering 1:1 comp time for that is the baseline, but I'd probably go to 2:1 or 3:1. Similarly with covering emergencies (higher premium if unscheduled) or holidays (I personally love working on most holidays, but if I had to get someone else to do it, I'd expect to pay at least 3 days of vacation per day).
1) Flexibility to take short vacations whenever there isn't anything to be done at work. This doesn't often happen in an early startup, but it's not too uncommon in a larger company to have a day or two where there is some external block. If you can work from home or otherwise be on email, there's no particular reason to just sit in the office that day.
2) I personally count most conferences, even when speaking, as vacation -- even if the company is paying expenses. Essentially, if it's something I'd go to myself, I'm happy to be going on the company dime, and it serves a lot of the purpose of vacation.
3) When long distance travel is involved, I'd usually strongly prefer to take a day or two before/after as vacation, particularly if it's somewhere interesting (which, for me, could be a lot of places). Sometimes this is at employee expense, but there are a lot of cases in consulting where flying someone back for the weekend is more expensive than paying for a weekend hotel. "Be reasonable" seems like the best policy for the expense part, but if you don't have kids or another reason to go home on the weekend, why not spend the weekend in Berlin or LA or something? (relatedly, I'm willing to use my frequent flyer miles to help the company on travel when it's expensive, in exchange for getting to use preferred carriers when the price isn't unreasonable.)
4) In ops, it's often useful to have people show up on weekends (for a consumer service, sure, you can push updates on Tuesday at 9am, but for enterprise stuff, weekend upgrades are actually pretty common); offering 1:1 comp time for that is the baseline, but I'd probably go to 2:1 or 3:1. Similarly with covering emergencies (higher premium if unscheduled) or holidays (I personally love working on most holidays, but if I had to get someone else to do it, I'd expect to pay at least 3 days of vacation per day).