I've only been to one of the character meals official, but have kind of experienced Storytellers.
Surf's Up at PCH Grill (breakfast) features Mickey (photo op), Minnie, Pluto, Daisy, and Stitch. I found the food to be pretty good (some unique items, some standard items) and mostly refilled fairly quickly on the buffet. The characters came around to the tables, but there was a bit of wait before the first one arrived. The characters seemed friendly and Stitch tried really hard to get the youngest of the little ones in our group to be less shy around him. It was cute for the adults to watch. I would not hesitate to return if I had a little one that liked these characters.
I've kind of experienced Storytellers' breakfast on a couple of occasions. I usually go for the first lunch seating, but that means the last breakfast seating folks are still there. Last time, breakfast had been extended to around 1:00 pm (due to crowds), so the characters were still making the rounds of the dining room when I was there (we stuck to the lunch menu, but were offered the option of the breakfast buffet). Even though we were doing the lunch menu, the characters stopped by and posed for photos with us (and everyone we could see regardless of which menu they were on). We saw Koda and Kenai (from Brother Bear), Meeko (from Pocahontas), and Chip & Dale. I can't comment on the food, but the characters were friendly enough and the bears seemed enthused when we knew their names!