Hi Allan, here's an example of why that "Edit points" mechanism in Rhino is just not good for actually editing a curve.

Here in Rhino I have drawn a curve through points, and then turned the "Edit points" to be on:



Now look what happens when I move that selected point:




Notice how the curve has become strangely lumpy and bent in the middle, and a strange hook has formed at the end?




When you move those "edit points" in Rhino around, you do not actually get the same result as if you had drawn a brand new curve through those points.

I wanted to add that in to Rhino mostly because there was a mechanism for it in Alias, I didn't really know at the time how bad of an editing tool it actually was going to be.

- Michael