
I'm a fan of this card, it has a funny way of increasing your odds at a test.
On standard, tokens tend to run the gamut of -1 to -4, they can be a nuisance yes, but they do not warrant Defiance level hate.
On hard/expert, those things can HURT. tend to be the most game-y with varied penalties from 0 to -4, god forbid the craziness that tends to key off them in campaign finale's. and strongly tend to be -3 with nasty effects, finally the varies heavily from campaign to campaign, in Core, Dunwich and Circle it's the "punishing token", with a huge penalty and often bad effects, in the other campaigns this token is more routine at -3 or -4.
The thing is, on hard, these tokens can influence your decisions and options so heavily that they limit your choices, some scenarios have tokens so punishing that if you're not testing everything at +3 you're screwing yourself over.
Defiance eases this pressure a lot.
The later in a campaign you get the more special tokens will be in the chaos bag, a few campaigns add very few, others pile them on like sprinkles on a 5'yr old's sundae. Obviously Defiance is therefore much greater value in said campaigns and so/so late in any given campaign. I would never go without it into the finale of Carcosa for example.
My best case for Defiance: It pretty routinely turns impossible tests (The kinda test where you say "Well, I'f I get a !") into something more like a 60% chance.