If you have not tried it yet, the new Variable Pattern introduce by SOLIDWORKS 2015 is a Game Changer. It is no longer a "normal" pattern but more of a generator of features.

You can reduce the feature tree length by a factor of 100 while making the changes in your design intent more predictable. It is a great automation tool, for sure.

Now, in order to fulfil its potential, we need some fixing of the 3D Sketching functionality, especially the robustness of relations and dimensions applied to 3D Splines, including Splines on Surfaces and Face Curves.

Please watch this video showing the attempt to control the positions of instances by dimensioning the distances as spline lengths measured along a 3D surface.

Should you find a better workflow, please share it with me.

Also, please disregard the last part of the video. I was obviously mistaken trying to match a 2 point spline on a higher grade curve.