coan.net: Interesting. It is true that dragon causes some kind of increased load but I have tried it on several computers and none of them was using more than 35% of CPU. Furthermore, it happens only with Firefox and Internet Explorer, Opera works smoothly and shows no strange behavior, most likely because its JavaScript processor is not as buggy as the one of other browsers.
Anyway, the code should not be loaded with other styles (except the castle one) and you can even turn off all animations, using a new switch "Enable style animations" at your Settings / General page.