[tophtucker]

Yeah, we at Observable love Vega-Lite (and Arquero etc). My coworker Ian wrote a great summary of how Plot relates to Vega-Lite here: https://observablehq.com/@observablehq/plot-vega-lite. Like you said, his first point is that Plot uses plain JavaScript functions instead of Vega Expressions.

Another difference is that Plot does more type inference, e.g. using d3.scaleUtc if the values are dates and d3.scaleLinear if not.

I wrote a similar notebook about Plot and D3, though the differences there may be more obvious: https://observablehq.com/@observablehq/plot-for-d3-users