Having done CRT breakfast in November and 1900 just last week, here's my opinion: it depends on what kind of interaction you want with Cinderella. At the castle, she only greets when you come into the castle. Your child gets a brief one on one before the official photo and then up you go to your meal.
The SAME Cinderella appeared at our 1900 PF dinner last week, and she came to the table to do a little meet and greet, and she also does a little waltz with Prince Charming and some interaction with the stepsisters. It's quite cute. The nice thing about 1900 is that she and the other characters make more than one pass by the tables if you time your dinner right. She came by our table twice, and that is nice if your child suddenly remembers she has to tell Cinderella something, etc. At our dinner, Cinderella chose a little "prince" to dance with. A-dor-able.
The stepmother by far is the whole reason for the season. She is hands down the funniest character at the dinner. Lady Tremaine has just the right touch of sarcasm and wit. We enjoyed her immensely. We also told Anastasia we loved her dress color and she whispered back, "I know, thanks, didja see her in that blue...uhhh-SO washed out!!"

They definitely play off of your comments and are very "on."
I was not impressed with 1900's dinner fare back in '05 but last week, I was pleasantly surprised. Yes, a few salads have an Asian flare, but they were delicious-- I went up twice for the very yummy edamame salad. There were plenty of traditional choices and such a great variety--I really have to put it right up there with CP's offerings. There were 2 meats at the carving station, and a number of pasta and chicken selections. The desserts were wonderful.