I find the interface really easy, I can concentrate on what I want to achieve rather than on the technicalities of which button to push etc.
My only problem with the interface of v7complete is the color scheme. Not in terms of artistic principles but in terms of being able to actually see what's on the screen. I can change the background of the viewing windows but not anything else. In particular in the function editor it is nearly impossible for me to see the little arrows for connecting the nodes- pale blue on white isnt the best choice...

"I paint that which comes from the imagination or from dreams, or from an unconscious drive. I photograph the things that I do not wish to paint, the things which already have an existence."
Man Ray, modernist painter
http://artpearl.redbubble.com/