I just stayed at Carousel last week and found it just fine. I would stay there again. (I've also stayed at Hojo's and Camelot Inn and found both of those fine too).
The pool is small, but the water was warm and my kid loved it. I think you can see the fireworks from there because it is rooftop, but we didn't try that. There is no hot tub as already stated.
The cont breakfast was fairly good as freebie's go. They had hard boiled eggs, oatmeal, toast, OJ, and different danishes. There were also apples, oranges, etc. and coffee or tea. Yes, it has a lovely view of the parks. My only complaint would be that it doesn't open early enough to eat there on an early entry morning. It opens one hour before park opening.
The Carousel layout is kind of strange in that most rooms are above ground level, like floor 2 and above. The cars park on level 1 under the rooms. We did have one of the rare ground level rooms in the back building. This room had hardwood floors and was clean and pretty. There was a fridge and microwave in the room. The bathroom vanity was separate from the shower/toilet which is nice if there are many people in a room. the A/C was rather loud when it ran, but we just turned it off at night. I found the front desk people to be very friendly and helpful.
For me, location is key and this is in a great location. After staying within walking distance on HArbor I won't ever stay anywhere else. Now I just pick from those hotels based on price (the free breakfast is a nice bonus). (And I avoid PArk Vue as it gets bad reviews).