Strange behavior between capsule and spehere

Hi all,
I'm posting this in physics because I believe it to be a physics issue. I've recently swapped out my stand-in character from a sphere to a capsule. All the same settings and components, except for mesh and collider, obviously. It has a rigidbody, and movement is applying a velocity to the RB.
The strange behavior I'm noticing is when the character goes down a slope. With the sphere, it was very smooth, no problems whatsoever. With the capsule, however, there's very noticeable stuttering, as if it's moving down a set of stairs rather than a smooth slope. Forward, then down, forward, then down.
There's no issue going up the slope, only going down.
When I brought this up to the other programmer on the team, he said he's noticed that in other projects using the capsule as a stand-in. So, anyone know the reason for the behavior? Is the capsule actually just a cylinder whose mesh was rounded but physics did not?

 

http://forum.unity3d.com/threads/unity-5-4-issues-with-character-controller.429446/
Using a capsule as a controller character, I have the same issues since I installed Unity 5.4
I came back to Unity 5.3 - even if it is not the best way to fix a problem

 

What version in 5.3? I'm running 5.3.5f1

 

I've done some testing and if I use a cube, I get strange behavior as well, but the opposite of what the capsule exhibits; the cube stutters going up a slope.
Also, upon closer inspection, it seems that when the capsule is going down the slope, it goes down slightly too far, ending up with a small portion entered into the slope, which leads to the object to jut directly forward as the character continue to move.
All in all, it's very strange.