For what's out there, this is probably one of a kind - superfast while being free and you can do what you want to the code. NO need to buy existing products. Just do what you want.
Opensource, free, fast. smaller than a picture
does take programming skills
I mean, there are a lot of charts but no one of them is that tiny like this: 43kB! It's excellent. It's unmatched.
Usability, Design, Size.
No cons at the moment
Take a look at the demos. I've never seen anything so gorgeous. It's stunning, period.
It's more fast, interactive and useful than a static picture.
It requires data (for now)
No issues found.
A great product. If you are a web developer and are looking for a charting solution you should definitely give this one a try.
Free, small file size, lots of themes and customizations
Can't think of any