If you ever plan to travel to Vietnam, take at least two days in Hoi An. I have seen a lot of citys in Asia, but Hoi An is one of the nicest towns I have ever seen; it is comparable to Suzhou in China.
As Hanoi is very busy and dirty, Saigon a very big town as well, Hoi An is calm, quiet, clean and very friendly people. You will find a lot of small shops, cafés, tailors and restaurants.
If you ever plan to visit Vietnam, come to Hoi An and stay there for a couple of days.
From Hoi An we drove back to Da Nang and flew down to Saigon and Mekong Delta.