I swallowed my pride and watched the latest episode, and my response is... Eh.
Sure, the production values are good, the plot was well-done (if a bit predictable), and there's a (expectantly contrived) moral for the kids ("If somebody tries to touch you in a place or in a way that makes you feel uncomfortable, that's no good!") but I failed to see what others see in it. Maybe watching more will change that, but I'll get back to you.
I was hoping the train would get attacked by a giant black cloud monster.