I've built a fair number of high-XP Seeker decks and I've never been that tempted to include Deciphered Reality. Oh, sure, the peak performance of this card is bonkers. In some scenarios you could arrange events so that you pick up nine clues in a single action. The rewards for a successful investigation are so high that combining it with Double or Nothing is actually worth actively pursuing (whereas most reviews' mentions of Double or Nothing are more like a fun thought experiment than a practical deck-building consideration).
But I'm not sold on it, and I think there's an important philosophical point we ought to unpack, there.
Arkham Horror CG decks should be built defensively. The consequences of succeeding a scenario are huge compared with failure - it could mean getting powerful allies, avoiding trauma and extra weaknesses, or even tipping the balance of success or failure for the entire campaign. By comparison, the difference between succeeding at a scenario and succeeding at it very well is typically an XP or two.
Therefore, cards that help you not fail are more important than cards that help you win harder. Deciphered Reality is a card of the latter type. You can only really bring out its full potential when you're in total control of your situation, where you can afford to have you and your other investigators spread out and exposing as many locations as possible to maximize the yield. If that's the position you're in, then you were probably going to win anyway.
Sure, in theory picking up a lot of clues at once can tip the balance between a win and a loss, but honestly? This is more clues than you need. Bear in mind that averaging one clue per investigator per round is extremely fast, and most scenarios will let you get away with half that pace, e.g. six rounds to pick up three clues per investigator. Massive clue-vacuuming plays are less important for a Seeker than just making sure that they, or someone else nearby, can keep enemies at bay so they can zip around the map and investigate at a steady pace.
If you don't specifically plan to use Deciphered Reality to make a huge play, then it may not even be worth using. It's not cheap at four resources, and there are relatively affordable cards to help you rapidly collect clues, like Archaic Glyphs: Guiding Stones and both variants of Deduction. Moreover, Pathfinder or a well placed upgraded Shortcut are great ways to cut down on the number of actions in a scenario, which is similar in practice to the payoff from Deciphered Reality, but they're cheaper and they're easy to use well.
On top of that, this card is just begging to be autofailed. If that happens, then you're practically guaranteed not to have time to pick up clues at all the VP locations that you deliberately didn't finish up, and could be at risk of failing the scenario itself. This game is meant to randomly generate huge setbacks. For the love of Yig, do not put all your eggs in one basket, like Deciphered Reality is baiting you to do!