Very interesting post, but your conclusion seems too strong. Presumably, if instead of messing around with artificial experiencers, we just fill the universe with humans being wireheaded, we should be able to get large quantities of real pleasure with fairly little actually worthwhile experiences; we might even be able to get away with just disembodied human brains. Given this, it seems highly implausible that if we try to transfer this process to a computer, we are forced to create agent so rich and sophisticated that their lives are actually worth living.