I just thought I'd leave this topic here. Not really a request to change stuff in the repo. But I hope this clarifies things for people who might wonder why stuff aren't working.
Note that the current Spine-Unity example has sprites at 1 pixel: 1 Unity/world unit.
SkeletonData assets also import skeletons with a 1 pixel: 1 Unity unit scale.
However, Unity examples and default scene, project and import settings show that the current optimum/recommended settings use the 1 pixel : 100 world units ratio. (This amounts to changing your SkeletonData asset's JSON scale import settings to 0.01. You can do this by selecting the SkeletonData asset in the project panel and changing the scale from 1 to 0.01 in the Inspector.)
Apart from just being based on old Unity standards, there are also currently some real roadblocks to being able to use a clean 1:1 scale in Unity.
A significant one is velocity caps in the physics system.
The topic was raised in the Unity forums here: http://forum.unity3d.com/threads/211307 ... D-velocity
One of the devs note that they didn't expose the velocity cap because they're not sure what might cause Box2D to break just yet, but it looks like they EVENTUALLY want it to be editable. For now, there doesn't seem to be a way around it except through implementing your own physics scripts which may not be able to interact with Unity's built-in physics integration (integration in the mathematical sense, which handles anti-tunneling and accurate physics stuff).
Another roadblock is the cast shadows don't seem to work very well. Not really sure if this can't be fixed without scaling down to 1:100. But LOD settings seems to be a problem for shaders that use cast shadows.