We did both breakfasts in October, and they were both good. Food was good in both places, but CP was a little more kid-friendly and less fancy. 1900 had ice cream though and HUGE bowls of candies for toppings that I had to hide from my 4 year old. A little too much for breakfast, you know?
CP also has the bonus of being in the MK, so you can make and early ressie and be in the park first thing and get right on the rides. 1900 is more leisurely, the Grand Floridian is beautiful to look at, but it takes more time than CP. Mary Poppins and Alice were wonderful at 1900, but my son liked the parades with the Pooh characters more at CP.
So, it really comes down to how much time you have, whether you want kids to get up and march around, and what characters you want to see. Have fun!