>>23275854Star to credits was about the same length for me (18 hours roughly for both), but that could be chopped up to people going through Gates faster because it's easier and have had previous PMD experience.
Main difference between the Gates story and the others was the characters. The cast were developed a fair bit in Gates, but not so in Sky where they were either overly dependant (the partner), pointless (the guild) or stoic (Grovyle and Dusknoir.) Still, Sky's special episodes did fix a lot of things for me, and I'd say that the Igglybuff and Grovyle special episodes were just as good if not better than Gate's best moments.