To move or not to move to Dusseldorf (Duesseldorf)

Hello- I was recently offered a job in Dusseldorf and need to decide soon whether I should move there from London where I currently live. I'm from New York City originally, and had been living in London for 3 years. I know no one in DUS, don't speak much German (but will learn), and after spending 1 day in the city am feeling like it's very small compared to the other cities I've spent time in. I think I was interested until it became reality and now I have real hesitations about moving and just wondered what those who have made the move already think! Please feel free to be honest.