This is a thought that occured to me on my way to classes today; sharing it for feedback.
Omega appears before you, and after presenting an arbitrary proof that it is, in fact, a completely trustworthy superintelligence of the caliber needed to play these kinds of games, presents you with a choice between two boxes. These boxes do not contain money, they contain information. One box is white and contains a true fact that you do not currently know; the other is black and contains false information that you do not currently believe. Omega advises you that the the true fact is not misleading in any way (ie: not a fact that will cause you to make incorrect assumptions and lower the accuracy of your probability estimates), and is fully supported with enough evidence to both prove to you that it is true, and enable you to independently verify its truth for yourself within a month. The false information is demonstrably false, and is something that you would disbelieve if presented outright, but if you open the box to discover it, a machine inside the box will reprogram your mind such that you will believe it completely, thus leading you to believe other related falsehoods, as you rationalize away discrepancies.
Omega further advises that, within those constraints, the true fact is one that has been optimized to inflict upon you the maximum amount of long-term disutility for a fact in its class, should you now become aware of it, and the false information has been optimized to provide you with the maximum amount of long-term utility for a belief in its class, should you now begin to believe it over the truth. You are required to choose one of the boxes; if you refuse to do so, Omega will kill you outright and try again on another Everett branch. Which box do you choose, and why?
(This example is obviously hypothetical, but for a simple and practical case, consider the use of amnesia-inducing drugs to selectively eliminate traumatic memories; it would be more accurate to still have those memories, taking the time and effort to come to terms with the trauma... but present much greater utility to be without them, and thus without the trauma altogether. Obviously related to the valley of bad rationality, but since there clearly exist most optimal lies and least optimal truths, it'd be useful to know which categories of facts are generally hazardous, and whether or not there are categories of lies which are generally helpful.)
How one responds to this dilemma depends on how one values truth. I get the impression that while you value belief in truth, you can imagine that the maximum amount of long-term utility for belief in a falsehood is greater than the minimum amount of long-term utility for belief in a true fact. I would not be surprised to see that many others here feel the same way. After all, there's nothing inherently wrong with thinking this is so.
However, my value system is such that the value of knowing the truth greatly outweighs any possible gains you might have from honestly believing a falsehood. I would reject being hooked up to Nozick's experience machine on utilitarian grounds: I honestly value the disutility of believing in a falsehood to be that bad*.
(I am wary of putting the word "any" in the above paragraph, as maybe I'm not correctly valuing very large numbers of utilons. I'm not really sure how to evaluate differences in utility when it comes to things I really value, like belief in true facts. The value is so high in these cases that it's hard to see how anything could possibly exceed it, but maybe this is just because I have no understanding of how to properly value high value things.)
I am skeptical. Do you spend literally all of your time and resources on increasing the accuracy of your beliefs, or do you also spend some on some other form of enjoyment?