I bought Descent directly when it got out. My experience with the basic set is that it is mostly very easy on the heroes. The OL will have a difficult time winning.
A year or so back I bought the Well of Darkness expansion. Playing with all the normal rules (incl. expansion rules) it became a real nightmare. We keep track of each players wins and losses with heroes and we're aiming for a 50% hero win. with WoD we went from 80% win to maybe 30% win (being optimistic here.. and to be honest basic Quest 7 already downed the heroes win% a LOT) We changed the rules now slightly (depending on the players):
The OL receives only 1 card per turn instead of 2 and no treachery. Now it is still very challenging for the heroes, but we have a win of 80% (average is still below 50%).
Last weekend we played the chase OL'ed by someone's second Descend game (first time OL), using the rules above.. until we had the silver treasure it was very challenging. We even had a few moments that our faith was literally in the roll of the dice (and we, the heroes, had the luck we needed to not loose or last conquest both times ). Once we had the silver treasures the stalling was over and it became a cakewalk.
I am wondering if we are alone in this experience and maybe do something wrong as heroes, or is this the general concensus about Descent+WoD ?