re: 3 weeks vs 4 week vacation

Tell them you currently get 4 weeks of time off, and ask if you can have 4? My company, as well as several of our competitors, will either match your time off or give you an added 1-2 weeks off immediately upon your hiring.

Another question to ask is,
- With the new company will you ever be able to get 4 weeks off and if so, how many years will it take?
- Does the new company offer a better opportunity to grow and receive improved raises?

I think if it takes around ~3 years to get bumped up from 3 weeks off to 4, or the company offers better growth/pay raises then it might be the better deal in the end. Definitely bargain for a week of time off when you sign your paper work so that you will get some of the time your losing back.