First author here. In addition to a declarative grammar, a big thing is the ability to scale past browser memory limits. The system works with a distributed P

First author here. In addition to a declarative grammar, a big thing is the ability to scale past browser memory limits. The system works with a distributed Postgres (Citus) to perform parallel hierarchical clustering to get the aggregation computed, and uses Postgres spatial indexes to fetch data on demand. We can scale to billions of records (see reddit comment demo in the news article). Also we are not limited to common representations such as circles. In fact you can create your own in D3. Here's a live demo of 1.88 million historical wildfires: http://wildfire2.kyrixdemo.live/ http://wildfire2.kyrixdemo.live/