Does Preference-Hedonism=Desire Satisfaction Theory?

Derek Parfait, the author of What Makes Someone's Life Go Best, mentions in his writing that what pains and pleasures have in common are their relations to our desires. More specifically he says that pains are unwanted experiences, and that pains are worse or greater the more they are unwanted. Similarly, all pleasures are when experience wanted, and they are better or greater the more they are wanted. Specifically, these are the claims Parfait associates with Preference-Hedonism. 

On the other hand, he also describes another theory. The Desire Satisfaction Theory. More specifically, he discusses a version of the desire satisfaction theory called the Success Theory. He argues that the success theory and preference-hedonism do in fact differ, but that they differ in only one way. The way they differ according to Parfit is that the success theory appeals to all of our preferences about our own lives while preference-hedonism appeals only to preferences about those present features of our lives that are introspectively discernible.
The claims made by Parfait made be want to take a closer look at the two theories. Let's consider these theories in the context of something that was recently in the U.S. headlines. In early February 2014, there was an outrage over the move on the part of a Danish zoo to kill a healthy giraffe, and feed it to the lions (http://www.cnn.com/2014/02/09/world/europe/denmark-zoo-giraffe/). The director of the Danish zoo explained that the zoo would euthanize the male giraffe named Marius because of a duty to avoid inbreeding. The giraffe's impending death had sparked outrage online, with more than 27,000 people signing a "Save Marius" petition, appealing for a last-minute change of heart. The petition was denied, and Marius was executed. 

This led me to wonder if this event makes the 27,000 people who signed the petition and who really wanted for Marius to not be executed worse off?

Through the lens of a Preference-Hedonist: It seems that on this view, depending on the extent to which the person did not want Marius killed, this pain or unwanted experience makes that person worse off to the extent that the experience of Marius being executed was unwanted. However, if this person heard about the petition, signed it, and then never followed up, and never found out Marius was in fact executed, then they are not worse off from the event having had occurred. 

Through the lens of a Success Theorist: The lives of all 27,000 people are worse off as a cause of the event of Marius being executed having occurred. This would be true whether or not they know Marius was killed because of their desire of Marius being saved, not having been fulfilled. 

Conclusion: While at a glance, the success theory and preference-hedonsim seem to be the same exact thing, it seems that when they are put into context, these two theories turn out to be completely different and the distinction becomes all the more evident as we can see in the above mentioned examples!