To answer this question we should define what exactly are we looking for.
1. aspect & durability
2. ease of maintenance
3. insulation efficiency
4. price & functionality
5. etc, etc.
The first European window I "studied" was in Germany 10 years ago.
I was impressed by quality, functionality (very nice mechanical parts) and beauty.
After I expressed my admiration I was told the nicer ones are made in Italy.
So the question is why nobody here in North America is looking at the Europeans?
Is it the pride or they are to hard to make and not enough profit...?
Sorry I don't have an answer yet!