First - while we have 5 weeks of vacation we do not have statuatory sick leave if a member of the family is sick. US has up to 2 of those. So if you have two kids under 14 in the family and both parents are working the numbers roughly add up to the same - 3 weeks of effective holiday.
You're severely misinformed. The US has 0 weeks of paid vacation, and 0 weeks of statutory sick leave. Yes that's right, you can get a job here that has no vacation at all. It's up to the company to give you vacation, in fact in many companies it's part of the compensation bargaining process. Some individual states have their own labor laws which may grant more vacation or additional rights. California does have quite a few laws, especially involving maternity, although they are nothing compared to what I've heard of some EU countries.
Culture - While I understand your bile I have to disagree with it. The highest productivity in Europe in the high tech industry is in the country that works least per day. Spain. The lowest productivity is in the country that works most - UK. This is actually reasonable if you think about it. If you work with your brain it does not help working yourself out flat and burning it.
I'd like to see a link to these statistics. While I would believe that if Spain in fact does have higher productivity, I'd only believe that it would be higher productivity per hour. Which does make sense. Personally I get the lions' share of my work done in the first 6 hours of any day. After that, productivity drops rapidly. I still get work done and am still productive up to about 12 hours. After that point I find working any longer to be counter productive.