I also got Secret of Monkey Island Special Edition and finished it the next day. I'd say total play time was less than 10 hours for the entire game, not just an episode.
Then again, I played it before years ago. But I totally forget things so for some of the puzzles it did take me some time to think about. And some were not obvious, like the red herring sea gull. I couldn't figure out what I had to do until I accidentally found the loose plank at random. Also there was the yellow flowers in the stew. I heard Otis mention that they were illegal to pick, but I don't think they mentioned that they were meant to be used as a sedative.
Even after getting stumped by some puzzles there was no way it took 30 hours.
I think the playtime of Tales of Monkey Island seemed just right. I'm sure after the whole series comes out I'll look back and feel that the whole length was as to be expected.