Note: I am not a Martial Blade Craft practitioner, but I will post what I have observed in the knives that I own and what I have read about these two MBC choices. Where Bowies come into play, I have studied them and their use as weapons up until relatively recently, so I am not entirely unfamiliar with James Keating and his Bowie Techniques.
As Martial Blade Craft knives, they seem to use two very different techniques. The Gunting is designed to be a system that goes from non-bladed, nonlethal form useful in punching, as a yarawa stick, and a "come-along" device that can inflict some very painful pinches on nerve points as well as being a precise hammer for hitting a nerve reflex point. It can also be used most effectively, from what I hear, as a bladed weapon if used within the framework that Bram has developed for it, The Chinook II, on the other hand, is essentially a shorter, folding Bowie knife and is intended to be used in that fashion, as best I can see. The trailing point would be extremely effective in James Keating's "back cut" technique that he developed for use with full-sized Bowies. I am also impressed with the heavy duty construction of the knife as balanced with the relative weight of it.
Finally, the blade on the Gunting is just under 3", making it legal in many areas where the 3 3/4" blade of the Chinook II would not be legal.