dgunbug

I really liked your schedule with the four days in Hanoi and more time in Siem reap. While we enjoyed halong bay, the drive too and from was so long and boring that we changed our original plans and canceled time we had planned to go to ninh binh as the thought of being in the car again dissuaded us (regrettably). Halong bay was nice, but extremely hot out on the bay and in retrospect, I would pass on it with such a short trip. I love the idea of taking one of the days from Hanoi to go into the countryside as suggested by crellston. Then, with an extra day in Siem reap, you can take a 1/2 day tour on tonle sap lake to see the floating villages where the Vietnamese have settled. We found that extremely interesting.
Hue is nothing like Siem reap, but very interesting all the same. A day and 1/2 is fine for hoi an, which we did enjoy - very picturesque. Whatever you do though will be wonderful and how fun that you will get to share this experience with Tom!