I like Rechan's better. I though Atras's adventure was a fairly straightforward monster hunt without much to differentiate it from other "kidnapped maiden" stories. I don't do 4e but I am left wondering how a bard becomes a powerful necromancer in order to have undead attacking on his behalf. The troll seemed very tacked on to me and hardly integral to the adventure.
Rechans had some weaknesses. I'm used to trolls being semi-animilistic monsters so their agreement with the village is a bit contrived for me and I do wonder why the cleric couldn't heal the third troll. I didn't know who Ioun was but assumed it was some sort of saint or diety. I thought the Ioun stone was really Rechan's weakest ingredient.
But if I ran both of these, I am pretty sure the adventure that would be remember 6 months later by the players would be Rechans, not Atras'.
More criticism than I would normally volunteer but the judge did ask for it.