Panoptes was a really cool boss that had the misfortune of being in an underwhelming DLC. His design was awesome and intimidating, and the fight was very cool thematically. People often ask for "single player raids". Panoptes was a single player raid boss. Add one or two more mechanics and he'd fit in with any other raid boss.
-
The encounter was kind of boring imo, however his design was pretty awesome. I bet it there was an additional mechanic to make it a bit more difficult he would fit as a pretty good dungeon boss.