I needed to make the same decision as you and decided to try 1900 Park Fare. We will be there in October so hopefully we'll like it. I made my decision based on:
1. the omelet station
2. the characters - Mary Poppins, the Mad Hatter, and Alice are not seen around WDW as much as some other characters.
3. not crazy about Lilo and Stitch
4. It's been a while since I've visited the Grand Floridian.
Lilo and Stitch are at the Ohana breakfast in the Poly, not the CP....CP does have an omelet station but Ohana does not (family style buffet brought to table)...
I do remember 1900 PF had a great banana syrup topping for the pancakes and yeh- the Grand Floridian is pretty spectacular on the inside...