What's your opinion on Highcharts usage longterm? I find it's great to get something up and running, but I've found myself hitting limitations, especially when it comes to custom design. But it's possible I may just be using it ineffectively. I always assumed that one day I should port my company's charts over to D3 if we wanted to be serious about our data visualization (which makes up a big part of our site).

In other words, is it like Bootstrap in that it's a useful starting tool, but doesn't really scale well if you want to have full design control in the longrun? Do you happen to know any notable sites using Highcharts? Thanks in advance.