Nozick’s experience-machine gives up too much to the hedonist, in letting hedonism claim as members people who might just value fiction or fantasy very highly, or have a solipsistic temperament, or not care much about contingent external facts. I’m sure there are some people who truly are prudential hedonists (this guy?), but I suspect that a majority of those who think they are prudential hedonists are actually prudential solipsists (i.e. people who only prudentially value their own experiential biography). People who prudentially value only their experiential biography may still prudentially value certain experiential biographies over others based on complex holistic properties that don’t reduce to a summation of the intrinsic pleasantness of the moments comprising each experiential biography. Machines more interesting than the experience-machine in this respect may be the the-experience-of-doing-confused-math-and-thinking-it’s-brilliant-math machine, or the machine that loops forever the experience of waking up on 5am on Christmas morning and falling back asleep a minute later super happy that you have an awesome active day ahead of you when you wake up.