At Trulia we have an unlimited vacation policy and it really does work for us. People routinely take extended, foreign trips of two or more weeks. This year I will be taking 4 weeks off in total, 2 on proper vacation and one week each with my family and my wife's.
So take this as an anecdotal data point. Oh, and come work for Trulia, we need great iOS and Android engineers desperately.
I don't find 4 weeks to be a "lot" of vacation time, but I think the hundred million workers or so who have 2 weeks or less every year would disagree that 4 weeks is "standard." On top of that I took 2 weeks of remote work.
That said, if you're an awesome engineer (especially mobile -- Trulia has about a dozen mobile apps to build out), and you want 10 weeks every year, lets talk. I don't hire for the mobile teams so I can't speak for them but I am certain that would at least love to talk to you.
But you've highlighted the problem I have with "unlimited" vacation. If I have to negotiate for 10 weeks, then I don't have unlimited, I have 4 weeks with possibly some extra but I don't know how much extra until i'm told off for taking it
No negotiation is required. The policy is 'we don't track vacation days' and that would be just as true for you looking for 10 weeks as it is for me who took 4. I'm not a benchmark-setter (or follower) I just happened to take 4 weeks so that's what I shared.
That said, you can't expect it to be considered in a vacuum. If you want to take 2.5 months of vacation, your work does need to be unimpeachably strong, and your dedication needs to be obvious to your teammates.
I think that depends on where you're from. Being in the US, my first job gave me the "standard" 4 weeks off, and I thought I was being spoiled by it. My current company only gives us 2 weeks off(ok, plus a week for Christmas but I only sort of count that..), and most people I know only get two weeks.
I think many companies dive head first into unlimited vacation policy without really thinking things through. I had a job where we had it and it somehow worked (despite the CTO's inability to follow any kind of project management structure).
Our PTO's were scheduled ahead which was policy. So if you took a two week trip, you filed it three months in advanced. You let your team, your PM, and business know you'll be out of town so they can manage expectations (e.g., less work). Our sprints were based on how much work we can do based on the existing resource. My team had a team of 3 so we never scheduled PTO's were two or more people were off for any prolonged period of time. Sometimes schedules collide, but we do our best to be transparent about big trips so that we can all plan accordingly.
You know, it worked well. I'm glad it worked well for you at Trulia (which, btw, helped me butt loads when I was shopping for a home, so thanks!). I'd work for you guys except I'm not a mobile dev, I like where I'm at, and I'm not looking to move. :)
So take this as an anecdotal data point. Oh, and come work for Trulia, we need great iOS and Android engineers desperately.