The last thing I did in D3 probably would have taken several times more effort with raw SVG and JS, I expect. I couldn't find a higher level graphing library th

The last thing I did in D3 probably would have taken several times more effort with raw SVG and JS, I expect. I couldn't find a higher level graphing library that would let me do what I really wanted at all (a custom radial graph that had fairly complex user interaction), and D3 was a perfect sweet spot I think. It gives you a whole lot of helper functions that really speed things up, data binding, animations, transitions, etc.