I really liked the idea of treasure-hunts, but I've got to say, I'm a bit underwhelmed by the execution.
The 18-hour restriction is annoying as these things go fairly quickly, so they can never be anything more than a minor distraction.

More than that though, it's the 'Find treasure'->Kill Mobs->Profit (Or die and get nothing for 18 hours) sort of set-up. Really would have liked the 'hunting' part to be more pronounced, and rather than having mobs guarding the treasure, it'd be fun to have some sort of minigames you have to complete to get the prize. :-(

Still probably one of the better parts of the update though. :-\