Seriously, try it. Come up with a design in your head. Try drawing it on paper. Then put the paper away, and try drawing it in Mockingbird or HotGloo. It will take significantly longer. And worse, it feels like wasted time, because you know you could do it much faster.
I kind of get the impression that the author hasn't done much wireframing
It would take ages for me to describe the exact interface I want and even then, as you implied, that may not suit others. So, rather than try to request an exact interface, I was trying to paint a better picture of what wireframing apps should be focused on. Less is more. At the moment, I think they are all missing the mark considerably.
If that was what you were trying to portray, it didn't come through to me; it looked like you were saying, "It should be convenient yet completely invisible."