You will be moving from country to country (different language, different culture, different rules and types of transport, differnt meal times, shop opening and days things are open and closed) every 2 days or so. It will take most of your time there just to get oriented.>

Well Thank God for the Euro - not long ago you had to change money too with every new country!

"I assume that most people who suggest spending longer time in each European city would also suggest to a traveler spending more time in those domestic cities"

No, absolutely not. I can go to Rome or Paris or Venice for weeks at a time and not be ready to leave. A couple of days in Chicago or St Louis and three in NYC, and I am done. There is no comparison between the sheer number of important architectural sights (buildings, churches, cathedrals), the works of art and the history in a city like Rome (or even Venice or Florence which are so small) and most of our American cities. When you are in many major European cities, there are also many very interesting places that are short, easy train trips. Simply walking in many European cities is more interesting and more pleasant than walking in some of our cities.

PalenQ, I actually miss changing money into different currencies. I do like having a cell phone and do not miss learning to use different telephone systems.

<<But although NYC, Chicago and LosAngeles are different - they are all in the US and have the same culture.>>

That's one of the most daft statements I have seen on this board.

The differences between NYC, Chicago and LA are minor compared to the differences between 5 or 6 countries in europe. If that isn't obvious - you have never been to europe.