CRT is in the castle and it books very fast. Usually within a couple of minutes of the reservations being opened up. That doesn't mean you can't get a reservation, you just have to keep trying, and sometimes spaces open up closer to the day you would like as people cancel. There is a reservation fee that they charge to your card and if you don't show up they will charge you the amount of the meal. I haven't eaten here since this went into effect so someone else will have to give you more details. CRT characters are there for breakfast only although they do serve lunch and dinner as well, just no characters. The storybook breakfast in Epcot Norway is a good alternative if you want to eat with the princesses. The food at CRT is very good and comes preplated with seconds available.
Crystal Palace is located across the hub from the castle att he end of Main Sreet before you enter Adventureland. This is a buffet with Pooh characters and the characters are at breakfast, lunch and dinner. The food is very good. You can usually get a seating here since there are three meals available.