Reducing shroud is a powerful effect in this game, but I suspect that, at least for the moment, Otherworldly Compass is going to have relatively few buyers.
Reducing shroud is usually better than increasing Intellect. That's because if you can reduce test difficulty to 0, you'll succeed on every token except for the autofail. This is why Flashlight is such a great card for investigators with low Intellect, like Zoey or Akachi, because it lets them pick up 3 clues from low-shroud locations nearly guaranteed. Otherworldly Compass has the potential to occasionally knock even a high-shroud location to 0, if everything works out right, which could be really powerful.
The problem is that it comes in the faction where shroud-reducing effects are least useful. If you have really high Intellect, like Seekers do, the advantages of reducing shroud vs. increasing Intellect go away. (Hence I usually don't run Flashlight in Seeker decks.) On Expert, with -6 and -8 tokens in the bag, reducing shroud from 1 to 0 will sometimes make a difference, but not that often. Reducing a 3 or 4 shroud location to 0 would be pretty nice for Seekers; but I think Otherworldly Compass will pretty rarely give you that much.
So for most investigators who can take it, Otherworldly Compass is going to be pretty equivalent to an Intellect bonus to a test of something like +1 to +3, once per round. I suspect getting +1 or +2 is going to be rather more common than getting +3. This makes the card inferior to both Magnifying Glass and Fieldwork, but a reasonable supplement to those cards if you're already running them and want even more Intellect-boosting assets in your deck.
Note that, unlike Magnifying Glass and Fieldwork, you can't combine Otherworldly Compass with other effects that require an Investigate action. So this card is a non-combo with Archaic Glyphs, Deciphered Reality, and so on.
All in all, I think this card is generally going to be substantially worse than Magnifying Glass and even Fieldwork for most Seeker builds. But I think there are two niches for this card. First, if you're a low-Intellect Seeker (Roland being pretty much the only one), this is a reasonable upgrade to Flashlight, with limitless charges and the potential to occasionally crack a 3+ shroud location. Second, if you can combine Otherworldly Compass with other shroud-reducing effects (like Arcane Insight
or The Skeleton Key), it looks more attractive. But this approach seems like a lot of investment that Seekers don't necessarily need to make, not even on high levels.