WDW has various levels of hotels. There are the fancy one like the Grand Floridian, the moderates like Caribbean beach, Villas, and the All-Star super cheapo almost Motel 6 types.
Disneyland has three hotels. Paradise Pier would be slightly better than the All-Star resorts and more like Caribbean resort. Disneyland Hotel has more amenities and is more like Boardwalk and Port Orleans. Grand Cslifornian is most like the Grand Floridian marries the Wilderness Lodge, lol.
Paradise Pier is plain and simple but still a great hotel. Ideal for cheapskates and families. Nothing really fancy but it does the job fine.
Disneyland Hotel is Cinderella who has seen her new sisters come and try to steal the limelight. She was the centerpiece of the Disneyland Resort. She has lots of amenities for conventions as well as families and adults who want a touch of class. She is one fine lady.
Grand Californian has the wilderness Lodge feel with lots of Arts and Crafts type of decor. It is upscale and is meant to be expensive and worth the money. It was crammed into a small space and put not designed with guests in mind at times. To get to the resorts you have to go down to the main floor then to the lobby then down a hall then out to the courtyard then through a walkway and then on to the monorail or park entrance. I would have put a main entrance on Downtown Disney. Great amenity for guests is close to the parks. She is the regal super deluxe hotel.
No one hotel is better than the other in my book. Nope. Each is for a different clientele. I would gladly take the Paradise Pier room any day just like I would take the WDW cheapo rooms. I love luxury but I am at the parks for the parks.