I don't think even three months is enough time, sorry. I spent about a year backpacking across Europe, living in the UK for 2 years and Germany for a year and a half. Even then, I don't feel that well informed to make such broad comparisons as you have done.
I would agree that the quality of life is better in many ways in the US, but it is at the expense of the poorer classes. In Europe, the distribution is a lot more fair, and so the quality of life is far, far, far higher on average.
As for services vs taxes..., not only do they have decent health care regardless of your income, which is a basic right in most 1st world countries, they have other benefits that the US is so far behind in it isn't funny.
Education...the children are actually educated. No child left behind nonsense, and no paying off student loans for a significant portion of your working life.
Parental leave...vacation time....all far ahead of the US, and contribution greatly to a greater quality of life.
The US is ahead superficially...big houses and SUV's....but it isn't sustainable, and we are starting to see that in this country.