Having worked with dc.js and D3 for interactive visualizations, I'm eager to try something else like this that could simplify charting. When recharting via an API, a lot of code needs to be written to handle it. With Vega though, at least from first impressions, it seems that all you need to do is pass a payload and you can immediately re-render. There's no need to run it through reducers or unpack and massage the data to get it to fit. I'm looking forward to trying it.