Ho boy. I admit I was a little gunshy going into this one. I'm basically in love with the PMD series and Gates kind of felt like a stab in the heart. The characters were just outright boring, the "problem" as I saw it was mostly informed and not presented. And the game itself just felt tedious. I couldn't manage to get through it.
But holy crap PSMD is such a breath of fresh air after that. I actually felt connected to characters and it managed to subvert my expectations multiple times. It is unfortunately a little short, I'm kind of itching for more and there are still a few unanswered questions that I have. But I honestly have to rate it better than Rescue. It'll take something pretty phenomenal to beat out Explorers, though.
So yeah, if you're still kind of skittish about getting this game, I at least recommend it.