1

I have not heard of Buffalo so I cannot comment on their longevity or professionalism.

However, as a general rule it's best to choose a traveour guide/program right where the program starts. That way you can assess and judge the professioianlism yourself, and usually you'll save a bundle.

Obviously, if you are very pressed for time (it often takes a day to get arrangements made), or if you have special needs that have to be addressed, pre-arrangment may make sense.

But experiences with tour agaencies vary a lot - from person to person, guide to guide, and just day to day. One person's wild adventure is an other's nightmare. And when you are with a group where other tourists are involved, it seems that who those others are determines a lot about the enjoyability of the venture (and that's something that can be somewhat assessed when you arrange on site).

Good luck!

2

Buffalo Tours has a very good reputation in SE Asia and in my dealings with them I have found them to be very professional.

3

You can check out some helpful reviews on TripAdvisor about Buffalo Tours:

http://www.tripadvisor.com/Attraction_Review-g293924-d1074223-Reviews-Buffalo_Tours_Day_Trips-Hanoi.html

Hope you find them useful and have a great trip!