I'm not sure which riser the 3dh most closely resembles, Orion. You're right. The throat is the same as the ST, however, the shelf on the 3dh is higher. The lower palm rise may be slightly slower on the 3dh than the ST, but I'm not sure. The problem I had with the ST was that my hand would ride up on the throat, causing the webbing of my bow hand to be possibly impacted by the arrow quill. To me, the angle of the palm swell rise to the throat felt like a steeper angle with the ST riser than with the 3dh. That observation may not be accurate though because the 3dh has a higher shelf radius than the ST, which may be skewing my perceptions of difference between these two risers. My hand, I noticed, does ride up on the throat of the 3dh riser too, but the higher shelf may be the difference. I also built up the shelf height a bit with leather, then velcro.