Widow eater: I must say I'm confused by your post as well. Never owned a bushbow, but have owned a bunch of critter gitters and ghosts and have a critter gitter on order now, with bamboo limbs. Compared to a lot of other mild r/d bows, the hand shock on all of the GN's I've shot has been mild. All bows have hand shock, of course. No bow is 100% efficient, and the extra energy in the limbs has to go somewhere. GNs have very small, physically light risers, so there's not much weight to absorbe whatever excess limb energy there is. Some are more sensitive to hand shock that others. I simply don't notice it on most bows, GNs included.
Part of the attraction of the bush bow and critter gitter for me is the mild r/d design that strings up into the classic D-shape. The trend/fad nowdays is the super r/d hybrid bow, often times with chunky, recurve type risers. They have more in common with a recurve than a longbow. They're faster than the mile r/d design, of course, all other things being equal. I've been there, done that. I'll take the stability (and looks) of a mild r/d bow.
I'm an experienced archer as well. Been shooting sticks for more than 40 years, and I'm also pretty good at it. If Great Northern bows have any flaws that require the shooter to compensate, I've yet to discover them. IMO, they're about as close to perfect functional design as one will ever see.
Re bamboo. IMO there simply isn't a better limb core material. I've converted entirely to bamboo cores. Every bow I own from several different bowyers have bamboo cores. In my opinion, bamboo is smoother drawing, it's a bit faster than wood cores of the same weight, and because it's physically lighter, there is less weight in the limbs compared to wood to contribute to hand shock.