This trip (we just returned from yesterday) we did a lot of Character dining after a quick bit of scrambling seeing how our daughter (nearly 3yo) handled our first Table Service meal (nicer meals were scrapped mainly for character breakfasts). It's kind of a 2 part thing based on food and characters, so I can give my thoughts based on our experiences:
Cinderella's Royal Table - Lunch - (Characters: Cinderella only for photos, Jasmine, Aurora, Ariel, and Belle at the table) - Food was ok, my pork was dry but my wife really liked her lunch (some form of meat pie I think), but it's not about the food there. We had great interactions with the princesses. The location, and wait staff was very good, and the princesses spent good time with each table as they walked by.
Tusker House - Breakfast - (Characters: Donald only for photos, Daisy, Goofy, and Mickey at the table). The food was very good with some nice offerings outside of the standard Mickey Waffle / Scrambled Eggs / Bacon-Sausage that they all have. The meal was lively and fun, the characters in safari garb was fun as well. Note: You have to pay for the photo with Donald if you want it, but the nice thing is that you do get a coupon for $10 off your next character dining photo (which did come in handy for us, each subsequent meal...).
1900 Park Fare - Breakfast - (Characters: Alice, Mad Hatter, Pooh, Tigger, Mary Poppins). The food was suprisingly mainly the standard buffett fare, with highlights outside of it being the smoked ham and the lobsters benedict. The ham was good enough for seconds. The characters were good here as well, when my DD got freaked out at the sight of the Mad Hatter, he politely and quickly moved on to the next table. Tigger was great, and Mary Poppins had my DD bouncing off the walls. We did have to spend a good amount of time here in order to see all the characters.
Ohana - Breakfast - (Characters: Lilo, Stitch, Mickey, Pluto). Outside of a bowl of good breads (Cinnamon Buns, Pineapple/Coconut Bread), the food served family style, was just a bowl of Mickey Waffles, Eggs, Bacon, Sausage, Potatoes. Kind of let down that there was nothing more exotic here in terms of food. The character interaction was great though, Stitch being a standout and one of my DD's current obsessions. The parade through the restaurant during mealtime with all the kids was great as well.
Overall, I was very happy with the character dining. I've heard good things about Chef Mickey and Crystal Palace, but we were unable to get into those on last minute notice.