I use it quite frequently! I ran several games set in there on GP in the past, and I'm currently running one live at my FLGS. Personally, I love it. It's big, it's "realistic", and it can fit so much. One of the biggest problems is that it is almost TOO much, and so you really need to hone in on what you're trying to run.
For example, I'm running Sword of Air, which takes place along the Gulf of Akados. This is what I gave my players to prep them for the game:
• The grand Kingdom of Foere, successor to the expansive Hyperborean Empire, crumbles as time and ambition begin to erode the very foundations, and peripheral nations begin asserting their independence.
• Battles for good and evil are very much real, as the gods and their champions struggle endlessly with Orcus and his dark servants, as well as other black gods and cultists.
• Cities are few and far between, and the wilderness that stretches between them is untamed and dangerous. Roads are patrolled often, but aren't without their perils. Ruins dot the ancient landscape, their original purposes often lost to time.
• The metropolis of Bard's Gate is one of the largest city-states in all of Akados. You can find anything in it, and makes for a good home-base in your expeditions.
• The Gulf of Akados is a landscape north of the metropolis of Bard's Gate, and has remained untamed since the days of the ancient Hyperboreans. It is filled with dark secrets and powerful beasts.
• The wizard Kayden has discovered a lead to find an elusive artifact, and is in need of brave adventurers to collect it for him.