Xmind looks cool. But...
Tried Prezi and Visio in the Past. However, to be very honest, I find those mindmap tools too rigid. I treat Design Docs as ‘Living’ Documents with intention to update/modify constantly as needed. They are more so Visual Aid for myself to work out: ideas, flow charting, design, art design. The only way the content solidifies is after implementation.
In regards to throwing blades, I concur that they are a bit hard to see when they come directly at you, but I just think the scale needs to be larger/thicker to solve.