So far it seems the best way to work with these new curtain panel pattern based families is to think through what the underlying structure is that you want to achieve, choose the most appropriate base pattern that matches that structure, and then drive your geometry with reference points first, then reference lines, and then planes.
Most of the examples of curtain panel pattern based families I have seen use splines that contort pretty well with whatever crazy mass you put them on. However, each panel and its spline is dimensionally unique. From a maufacturing point of view I was wondering if you could make these curves identical from one to the next so you get the economies of mass production. Here is a sample based on pine cones and fish scales that uses repeated identical discs. The tilt, radius, and position of the discs are adjustable as well as the material. The discs are connected to a triangulated frame.
Below is another panel I made based on a real pre-Revit 2010 project. When we first made this, it was difficult and clunky because it draped across a curved surface and used a lot of voids; but it was a breeze to make with Revit 2010 with crisp seamless edges and no voids.
And here's another with a litte help from the API and instance parameters:
This Spanish tile panel pattern might not perform well for a big roof, but it is possible and looks great (the ridges are a line-based family):
And now for some impractical but fun stuff showing off Revit's curvy abilities. The curl and width of each leaf is adjustable with instance parameters so you can get this:
or you can even adjust some visibility parameters to make the 2 additional types from the same family as above seen here: