In Design Studio all installers are self-contained and support full installation or upgrade from any lower version.
There is no need to install SP0 and make upgrade to SP1 - SP1 is already self-contained.
Change on Java Script Load
One improvement in Support Package 1 is the way how java scripts are loaded. In short sentence, the load of java scripts is no more application sepcific and this allows better caching on client side. Details in the SAP Note