I've used Signgo for 7 years and I love it. I don't know what 'contour cutting' is either.
I use Illustrator for all of my designs, export to eps and import into Signgo. It has drivers for both of my plotters and you can split your design over multiple pages, cut multiple designs, flip it, rotate it, only cut certain colours..
I don't really understand what you guys wish it would do better?
This is my first post here btw