has anybody ever polled/researched about the balance of quests?

By kookoobah, in Descent: Journeys in the Dark

anything like the win ratio thing they used to have for battlelore over on DoW?

The problem with this is the number of factors that play into a win or loss.

Anything from the skill of the individual players to the hero/skill combinations to the randomness of the OL deck. Not to mention the dice, treasure draws, or tactics employed by either side. I have seen several posts on these forums talking about the balance or lack there of for a particular quest or expansion.

My findings would definately differ from other players' experiances. The research is too subjective and the forums can be searched for unbalanced and you can find a number of quests that players tend to agree on.

This thread on the BGG forums includes some statistics and analysis of the base game quests from one playing group.