We have been using Highcharts from version 4.x to current version 7.x. my overall experience is just awesome with Highcharts library.
Main advantages are below:
2. Easy to use because of coding standards.
3. Free documentation is available on official website.
4. It is free for non commercial usage
5. It support multiple axis design.
6. It is working on cross browser and don't need flash play at all and i love that.
7. We can export the chart as PDF JPG and in PNG format as well using one click.
It feel hectic and irritating when we have irregular data for time range of more than one year and it crash the browser sometimes when rendering graph with low volume of data it works perfact.
Licensing price is quite higher for corporate user.
We are using it for 2 axis only like Mega watt on y axis and time on x axis.
Sometime we have per minute bar data on y axis and user can exactly check by zooming on chart with zooming options. User don't need to look at the profile grids.
User simply scroll the graph and take decision how the energy is flowing over time.
So we are using it in Energy and Trading applications.