Hi there!
I haven't stayed at the Best Western, but have stayed at both the Hotel Royal Plaza, as well as the Courtyard by Marriott.
Marriott: The Marriott has the biggest rooms on Disney property, including the Disney resorts. The rooms are spacious, and clean. The pool is nice, as is the hot tub. The staff was very attentive.
My only real problem with the Courtyard was the food. The restaurant had iffy hours, at best. They also had no room service when the restaurant didn't have hours. The snack counter had medicore choices. If you stay here, request a pool view tower room. If they can't get you pool view, TAKE A TOWER ROOM! The rear wing is REALLY far back, and after a long day at the parks, it's a LONG walk back. All of the rooms and views are the same, so you won't have to pay extra.
The Hotel Royal Plaza: I'll never understand why Mary rates this the way she does at Mousesavers.com Maybe if you have a tower room instead of a garden wing room, it's better. But the room was falling apart. There was rust and mold on the ceiling, large chunks of drywall were missing in the sink area of the bathroom. The hardware on the curtains fell asleep, and the paint was falling off of the patio door. There was one elevator servicing the ENTIRE wing. It was an incredibly long walk from the back. I didn't eat the restaurant, so I can't speak for the food.
The bussing system is the same for both of the properties. All the Downtown Disney hotels share a bus system. Many have said they've had problems with busses, but I have never had any problems. I've always had a seat, and knew when the busses would be in the parking lot as they were on a schedule. I've never had to wait for one, whereas I waited 20 minutes for a bus from MGM to Port Orleans Riverside.
If I had to choose between the two of them, I'd pick the Courtyard hands down. Any food problems were remedied by the fact that Downtown Disney was ronly about a 5-10 minute walk.
Sorry I can't help you with the Best Western. But it looks really nice, and if I could get a good rate, I'd stay there.
If you're looking for the "Disney Magic®", you won't find it. If you're looking for a clean, reasonably priced place to stay, you'll enjoy it, I'm sure.