The problem I have with protoytype tools and GUI framework implementations is that they typically contain a simplified and limited collection of controls. In the world of atoms you can find lots of different knobs, but in the world of bits you will typically find the controls the same collection as +10 years ago. Maybe this is because the programmerism of the days programmers thought they could construct a usable GUI mere by some simple form design tool have not been over yet. I don't feel in control when using the modern prototyping tools. I feel they restrict my work to superfical bulky looking products. The other thing is that: not one of them is tailored for the complete workflow of interaction design. Those tools being so limited make me more feel like a developer than a designer most of the time. If you would have _one_ (not yet existing) tool which you could use for your entire workflow in interaction design, what interesting features would it have? How would it not be like the stuff we already have?