I really, really, really love this card. I was amazed by it from the first moment I saw it. But it's really sad that very few investigators can actually use it. The problem is its high cost and the fact that the only reliable Survivor weapon is Fire Axe. Most Survivors who can mainly use only Survivor cards will almost always use Fire Axe as their main weapon and that leaves no allowance for them to use this card, as a Fire Axe deck usually stays slim in recources. The only Survivors who can play efficiently without Fire Axe, thus be able to use Will to Survive, are Wendy Adams and William Yorick (there's Lola Hayes too, not a Survivor but she has access to it). I wish there was a more expensive version of this card XP-wise that cost less (5 XP for a 2-resource discount, let's say). If such a card existed, it would open up a lot of options for many Survivors and it would be a solid upgrade for any of them, as well as a great way to spend left-over XP. "Ashcan" Pete would go for Key of Ys less often and William Yorick would have more (in number) solid options to spend his XP on other than getting The Red-Gloved Man. But anyway, that is a different matter.
While Will to Survive is a great card by itself, where it really shines is when you combine it with cards that give you extra actions, and, thankfully, both Wendy Adams and William Yorick have access to cards that give them extra actions (via Leo De Luca and Quick Thinking for Wendy and Police Badge for Yorick). Now, there's Lola Hayes too, who also has access to all of these action-generating cards, along with Ace in the Hole, but apart from Leo De Luca it's kinda hard to use them in conjunction with Will to Survive because of her role mechanism. Combined with these cards, Will to Survive can be a beast, allowing you to deliver heavy loads of damage or pick up a significant amount of clues from a location in a single turn, as long as you have set it up. Guidance and Shortcut deserve a mention here, as both of these cards, each in its own way, can help set-up those big turns when played by your teammates. Guidance will directly extend the turn of the investigator intending to go for that big boom, while Shortcut can save you from the trouble of having to move into the location of interest.
Another thing to note is that Lola Hayes will be able to use Will to Survive in conjunction with the upcoming Borrowed Time in order to save up to 3 actions for next turn to have up to 6 actions with Will to Survive!! Theoritically, she can already achieve a 6-action turn with Will to Survive using Ace in the Hole, but that card is generally harder for her to use due to her role mechanism, while Borrowed Time's effect will be generally easier for her to use, as its forced effect will take place regardless of her current role.
Anyway, Will to Survive is an awsome card, somewhat expensive even for a Wendy rolling in cash from Rogue resource-generating cards sometimes and it's always worth the slot if you can support it. Also great card for recursion via Resourceful and Wendy's Amulet.