Perception, Guts, Overpower, and Manual Dexterity are by far most cost efficient and overpowered non-asset cards in this game. Usually a good card is something that gives us an equivalent of getting 1.5 actions per 1 action (example: 1 action to draw Emergency Cache, 1 action to play it, and you get equivalent of drawing 3 resources). But Perception only requires to draw as an action, committing is not action, as an example we'll take The Gathering scenario standard difficulty which has 16 chaos tokens:
- If Shroud 4 and Lore 3, we have 2 success tokens, Perception gives us +8 success tokens against 37.5% chance of not replacing Perception card, or 21,3 success tokens per spent card (10.67 per 1 card/action efficiency).
- If Shroud 3 and lore 3, we have 6 success tokens, Perception gives us +7 success tokens against 18.75% chance of not replacing Perception card, or 37.3 success tokens per spent card (6.22 per 1 card/action efficiency).
- If Shroud 2 and lore 3, we have 10 success tokens, Perception gives us +4 success tokens against 12.5% chance of not replacing Perception card, or 32 success tokens per spent card (3.2 per 1 card/action efficiency).
How i calculated numbers above ^, example: assuming no ghouls in your location, taking one plain action to retry Lore 3 against Shroud 2 test without committing resources would give us a chance of drawing 10 success chaos tokens from 16 total tokens, or 62.5% of success, vs. Perception committed it's +4 tokens. How much does committing Perception costs in cards/actions_to_draw_a_card? It's the chance to lose Perception, which is the amount of losing tokens (2) against total tokens (16) = 12.5%. Multiply 12.5% by 8, and you get one action you will spend to draw a card, also multiply 4 tokens by 8, and you get 32 success tokens for one draw card action vs. 10 success tokens of taking another plain research action. 32 vs. 10 = 3.2 as efficient.
And that's not even taking into account its deck thinning ability, 5-8 of these cards will give you the same or better deck thinning than Underworld Support, but 1) without limiting good cards to one copy, and 2) you can commit these to help other players.
The upgraded versions of these cards are not nearly as cost efficient.
I'll remove the review if my math is wrong.