We just came back one week ago from the Royal Plaza. I booked through Hotwire ($63/night) and was given a standard Lanai room. I hated the room, and it smelled extremely musty. The girl at the front desk did eventually switch us to a Tower King (room 605) which did look just like the picture on their website. That room was extremely spacious and overlooked the pool.
The pool is about 4 feet deep at the most shallow end (if you have small children). There is no kiddie pool. The jacuzzi was pretty large. They do have a pool bar which seemed nice.
Their restaurant is pretty good and a nice break from the Disney prices.
The hotel does not qualify for e-nights. You can do early entry, but if you really want to go to the parks early, be at the bus pickup area for the 7:00a.m. pickup. The next bus won't arrive until 8:00a.m.....then they're supposed to run about every 20 minutes, but it's more like 1/2 hour. We always had a seat on the bus when picked up at the hotel....I think the buses pick up first at the Hilton, then the Marriott, then the Royal Plaza. However, if you're leaving MK at closing, you may not get a seat on the first bus. Sometimes there are several buses already there waiting, sometimes there were not. I was not thrilled with the bus service, but it was adequate. They are very comfortable, though.
Overall, the Royal Plaza is on par with a 3 star hotel rating. It was renovated about 2 years ago. The people who work there are very friendly. The lobby is nice. The newer room we were moved to on the 6th floor was great. I don't know about the poolside Lanai rooms, but I would stay away from the ones facing the parking lot. I would definitely consider staying at that hotel again for a different vacation.....I did feel slighted by the transportation.