For all you guys that are looking for some hard quests, these ones should satisfy you. I have played the first two a bunch of times, and they can be quite brutal.
There are conditions that cause you to either add a nasty enemy to the encounter deck or choose something like raising your threat a bunch/revealing another encounter card. Lots of surges. Just took Thorin and Co. to the Prancing Pony and had a turn 1 loss due to a Black Rider making multiple attacks.
I have been able to beat them a couple of times, but certainly more losses than wins, especially with a Hobbit deck.