That's very interesting. I've never seen a gimbal with the camera mounted on the side, not the bottom. Is that unique to the Tomahawk?
TBH, I don't know. This is my only experience with a gimbal.
But, just let me say that this is a very comfortable way to "hand-hold" a large heavy lens. Since the camera/lens is balanced on the gimbal with all the weight transfered to the monopod, it is essentially weightless to the photographer. And with the single hand control of the up/down adjustment to the monopod and the ability to point in any (every) direction, it is just like actual hand-held without, of course, the "shaky" hand.