My basic review:
There's a lot to like but as an overall package, I found the ride to be underwhelming. The ride is an enigma of sorts. Creative and kinda lazy? The projection effects are really crisp and clean, but outside the first room (the desert room) and the final room (which is a very impressive transition), it feels cheap; mostly due to the fact that it's filled with props instead of a room with 95% screens. The pre-show effect is great, and a very clever way to transition into the cartoon world. I'll admit, I do not like the animation style of the new Mickey cartoons - and some of the AA's look very awkward, specifically the first pair of AA's in the car. The tornado scene feels like an afterthought and almost as they ran out of money. The Daisy dancing scene feels like a completely random, forced moment (probably to add to the ride time to help with vehicle dispatching) and a total WTF moment. During our ride, we started out on the last train, and due to that, we completely missed the jungle/volcano scene. I also wasn't a fan of the waterfall portion. Because the ride is overwhelming with visuals, it forces you to look around; so because of that, the ceiling with all the production equipment stands out more.
As a supplemental ride, this ride will be fine in Disneyland (and ultimately, be fine here), but in the context of DHS, the ride needed to deliver more. I don't think of it as a worthy replacement of Great Movie Ride. GMR definitely needed an overhaul and understood why it needed to go, so this isn't a case of sour grapes - but this could've easily taken over something else instead of the main weenie of the park.