@Alcemon - ah i see, then i think it is simply a case of how the function in the program handle things
system - create - each sprite can be set and individual instance variable while the spawning is happening
sprite - spawn object - setting variables while spawning keeps the original sprites values (in my experience)
you can do a workaround to get the desired behaviour (using system) or you can use a workaround inside of using sprite - spawn another object.
this seems handy in that say you have an enemy you could have it spawn direct clones (using sprite spawn another object) or have it spawn weaker clones (using system and setting its health variable or defense etc).
i will have a look again later and look for more ways to accomplish what you are hoping to achieve within sprite spawning another object