I would like to second this. I also did a project using d3 this year, and everybody I've shown it to has been really impressed, especially in "management".

It took a bit of investment from my side (i.e. I did not book all the hours) but I knew that the return on it would be awesome, and it is. And that's even though I hadn't made a single line of javascript for over 10 years.

So thank you mbostock !