I have the Sky TDX13 and Dryad Epic 13" risers. Both are are great risers. The TDX13 has AMO sight/quiver holes and twin Berger holes if you find that useful, but it lacks a front stab bushing.
I found the TDX13 to be more of a 14" riser than a true 13", and it seemed to buck the "1# increase per 1" reduction in riser length" rule of thumb. As an example, I mounted a set of W&W WinAct 40# medium limbs (rated on a 25" riser) on the TDX13 and at my 27" draw, it only registered about 44# with limb bolts in.
I'm in the same boat and interested in the responses as well. I have a set of extra long Morrison longbow limbs and until now I've been shooting them on a Black Bear Warf. Love the limbs and the riser but in a hunting situation that 68" is gonna only grow longer so I just bought a 15" Sky TDX, waiting for delivery.