SciChartJS is an amazing library and blazing fast. The APIs are extremely well defined, documented and easy to use. We are displaying multiple charts with each one having around 6-7 million data-points without any issues. The memory consumption is fairly low as well (around 400Mb). I am extremely pleased with their customer service. I had opened several tickets (not bugs), but more like "how to do X or Y" and they have always responded in a timely manner (< 12 hours). The solutions they provided me were pretty much to the point and exactly what I had intended to implement. Overall, I am very pleased with our subscription with SciChart. I would give them 10 STARS or more if available.