Yes, the service is excellent, and they are often 15 mins prior to our booked time. For Airport - Hanoi, I often take the elevator from Arrival to Departure hall, bargain at any taxi outside, it is about VND 300,000 as of Jan 2012 from the airport to Tay Ho area, 20% cheaper than in arrival area as most of taxi have to come back to Hanoi with their empty cars. Depends your time of arrival in Hanoi, if it is after 21h, I recommend the regular airport taxi just outside of arrival hall. If you are free from your luggage, take a bus, which is VND 30,000 to downtown. Kumho bus is my choice. They parked by the end of the terminal, at your right hand.