Quest Rewards (Sacred Pool expansion) are alternatives to Talismans for completing Warlock's Quests. However, on occasion, I find that the cost of completing the quest isn't quite worth the reward!

I usually choose a Quest Reward if it is the early game (as they can't be stolen, unlike Talismans), and if the quest is a travel quest - such as visit the Tavern, or visit the Enchantress - something easy. A heavy penalty like discarding two followers sometimes isn't worth it!

Also, I find that using only the Reaper expansion (without Frostmarch), whereby you can choose your quest, makes the Quest Reward system much more advantageous. When the Frostmarch cards are added and they are drawn randomly, it's less predictable.

When do you choose Quest Rewards over Talismans?

I almost always choose the rewards over Talismans, because, the Talismans can be obtained from other sources. The quest rewards cannot.

It greatly depends on the course of the game. There are games where no Warlock Quest is completed or even taken, while there are others where they become important for some reason, not only with Warlock Quests and Sacred Pool Endings.

If I happen to find and complete a Quest in the early game, for example from a Lake of Visions where I can choose a quest out of 4 available, I would surely get a Quest Reward. Some of them are absolutely not exciting, but there are several that can help you when your character is weak. Moreover, a Talisman only occupies a slot in your inventory, can be stolen by others and you won't need it until the very last moments. I would only keep a Talisman if it's gained in another manner, not if I have to complete a difficult Warlock Quest. In this sense, Sacred Pool added a great option with Quest Rewards.

I've never played choosing Warlock Quests, not even before Frostmarch. If the base game rule is to get a random quest, I considered Reaper WQ rules to be an oddity from the beginning and Frostmarch rules only confirmed that.

And if I may add to the discussion, which ones do you consider the most useful Quest Rewards?

If I had to choose 3 cards out of 24, this is my top list:

1) Moon Charm

2) Gift of the Wild

3) Ancient Names

Bottom 3:

22) Weaver's Mark

23) The Magic Door

24) Vast Wealth