This is looking pretty good Lara, how are you constructing it is it using Loft?

If so one thing you could experiment with is setting the Loft style = "Loose" option. That will make a loft that does not exactly pass through each station other than the first and last but it could give you the softer shaping that you want. With a "Loose" loft the surface will behave similar to how a freeform curve with control points behave, where it's only forced through the first and last point and generally guided by the in between ones.

- Michael