Since static templates are rendered on the server side, there is no delay when displaying these on the frontend. Other shortcodes need to wait for the JSON API. In addition, if you use static shortcodes only, you can and should disable polling, which should improve things a bit.
The main motivation behind static shortcodes is that you can have one page for each coin, rather than the user being able to select between all the different coins. A lot of people have requested this.