Just back from the 17 Day (Land + River) Tour with Emerald Waterways. 2 nights in Hanoi, 2 nights in Halong Bay, 2 Nights in Saigon (Ho Chi Minh) then onboard the Emerald Harmony on the Mekong for 7 nights. This was followed by 3 more 'land' nights in Siem Reap. Fantastic trip!!!!
I do plan to write a more detailed review, but one thing that is really nice about the Emerald Harmony is that she docks right in Saigon. My understanding is that many of the river cruises bus you from Saigon to My Tho.
I was worried about the Emerald cabin because it has the fake balcony and the window just comes down. The reality is that it is so freaking hot, you rarely sit with your window down. There are many, many nice areas outdoors if you want to find a place to sit and read. Also, while the Mekong is interesting and there are many great villages to visit, the actual scenery is not worth sitting on a balcony watching the world as you sail by.