You can't please anyone. I would say listen more to Trip Advisor. The Carousel is lovely as it is on my top two places to stay when at
Disneyland. 4 of us adults in one room and we never complain about the size of it. Yes it's a motel, but it is clean, the rooms look very nice, a great location, the service is pretty good, the beds comfortable, a decent free breakfast, and they have a decent rooftop pool. I have never had a noise issue other then the occasional person dragging luggage as they walk by or kids excitedly talking in the morning. As long as you understand that you are booking an average sized motel room, and not a 5 start penthouse suite, I think you wont have a problem. This is Disneyland, where many people visit, and I am sure they have to condense rooms slightly to accommodate more people. Also to keep the popularity of the place or even the motel running, they have to keep up to certain standards. At the end of the day all anyone really looks for is a room to shower and lay their head. You wont be spending tons of time there anyway. I say save your money and stay where you can walk to the park easily.