The character assortment is better at CM's (Mickey, Minnie, Goofy, Pluto and Donald Duck). It is loud and rowdy, bright, monorail rolls overhead, there is singing and dancing, a lot of fun and they'll take a family photo before you get seated (optional to purchase). I loved the 3 cheese omlette, Mom loved the Goofy's lasagna.
PP - sorry you missed the pastries to include Krispy Kreme Donuts at CM's; wish I had....lol
1900 has Pooh and the Mad Hatter, quieter venue and the ice cream machine is on during bfast. I think you can get a made to order omlette here too.
I think the food will be god enough at each.
We took our 5/6yo to CM's, over a year later he still talks about it and we will return next trip.