Beware!! Hanoi transfers won't necessarily leave you at the right hotel!
We got to Hanoi after 21 hours travelling, and were left with another couple at a hotel. Turns out we were on different tours, they were in the right place, we weren't and the minibus had cleared off! Luckily the hotel managed to get us a taxi and our tour leader refunded the cost but the moment of panic at being in the chaos of Hanoi late at night and not knowing where you are wasn't the greatest..... also having paid for a transfer to our hotel, we assumed we would be left at the right hotel.
It all worked out in the end but just a warning to others, check you are in the right place before the bus leaves!