I like these cards. They're a good mix of 20 outcomes. I use them with Fate, letting the players decide how we're going to put them into play (random draw, draw from a face-up pool of five, etc.). The cards are useful in a few Fate mechanics: when a character gains a Boost, when an action succeeds at a major or minor cost, and when a character takes a Consequence.
My players sometimes struggle to come up with ideas on the fly for such things, so these cards offer inspiration and variety. They help create dramatic moments in play.
We dial the intensity up or down according to circumstances. For example, if an attack ties and we apply the Snares card as a Boost on the defender, the defender is entangled only briefly, such as catching a sleeve on something for a moment. If a character succeeds at a major cost while trying to open the door of a sinking car, the Snares card could mean the car door is now open, but the character is entangled in the seatbelt while the car continues to sink.
I also like using the cards in Fate Contests. Each side scores 0-3 victories before the contest is over. I want each contest victory point to mean something within the game world instead of being an abstract number. If a PC is trying to sneak up unnoticed on a guard, for example, each victory for the PC reaches another waypoint leading up to the guard, while each victory scored by the opposition applies a danger card to the situation. This lets the attempt become more dramatic, if the PC's foot gets caught while sneaking up, for example, or if the PC drops something along the way. We let the Failure card end the contest immediately (e.g. the stealthy PC is suddenly, totally revealed to the guard) instead of waiting until one side or the other scores their third victory.
A corresponding set of "benefit" cards could be welcome, but these cards can still be useful for beneficial effects: Use their opposites. A beneficial version of Injury, for example, could mean heroically ignoring an injury ("'Tis but a scratch!"). The Snares card could mean something becomes disentangled. The Expense card could mean suddenly replenishing a depleted resource. And so on.
[5 of 5 Stars!]