I just completed "The Void Stares Back" a few days ago. This is considered a Grandmaster quest, but its by far the easiest one and I found it incredibly easy to complete. The quest would be much harder and take far longer if there weren't guides on the internet on solving the puzzles throughout the quests. As long as you follow a guide, it shouldn't take you more than 2 hours. The hardest part is the Pest Queen, and even that part is extremely easy if your a high CB level.
If your low combat or don't meet the reqs, then this won't be a good quest for you. I just thought I would suggest it because I was surprised just how easy it was for a supposed "Grandmaster" quest, and the experience rewards are fantastic!