We just did Lilo and Stitch a few weeks ago, and it was the best we've ever done! The character interaction was great, Stitch sat down at our table and played with our son more then once! As you can see from the picture in my avatar. We got to see Donald and Daisy (which you don't see either very often), Max, Minnie, Lilo ect... The food was really good too.
We usually go to Goofy's, and have had some hit or miss experiences. Personally I think going early is key. The later you go, you start to hit slow times, where the characters may be taking breaks ect... I think that can happen at any of the character breakfasts. So in our experience, timing counts.
We've never done Minnies in the park. We did do it back in the day when it was at PP. For us though, once were in the parks in the morning we want to start hitting rides. So we've always just done a nice early breakfast at one of the hotels.
But we were really impressed with Stitch at our breakfast, he really went above the usual posing for a picture and saying hi. My son just loved it, and we had to go buy a Stitch stuffed animal afterwards. His new favorite character! LOL