Either one is great although I have not flown the S12 yet I here it does 3D well. I would think that the Eagle does not do 3D well as it is a short coupled plane

Now I have owned the CG Ultimate and using a YS 110 turning a16X6 APC and it was a 3D monster and had absolutely no bad tendencies although it's not a 120 size. The flatest flat spins you have ever seen, Would hover at 1/2 throttle, Knife Edge loops as big or small as you wanted, A Blender that wound up extremely tight and fast. It did a lomevac like you have never seen before.

The DP Ultimate is a 120 size and I have seen one do everything my CG did using a YS140 Sport turning a 18X6 APC. In my opinion, if you want a really good 3D bipe, any of the Ultimates will do.

You also have:
Chip Hydes Double Vision (Ultimate built around a DA-50)
Hangar 9 46% Ultimate (An Ultimate on Steroids)
Areoworks Ultimate


As you can tell I think the Ultimate series would be your better bet for 3D