Honestly-I have only been there in winter. I believe it is pleasant., warmer than the UK. I have a sister there, and it can be pretty miserable.
Utrecht is also great-and a younger, university type population.
A week is not much to decide if you want to move there permanently......but it IS a great place! Highly recommend it!
In fact-when I see my hubby next week we are booking a river cruise for next year-Amsterdam to Budapest.
My hubby is MUCH more familiar with Holland than I, as he was going there are least 4 times a year for about the past 15 years for business......his partner is Dutch, as are many business connections.