When we were there in May for our first family trip, we did 3 character breakfasts. At each restaurant, we had the earliest reservation of the day. We LOVED doing this. And would possibly do them all again. I know that we were fortunate to be able to budget for this, and I also know we were lucky in the situations we found right after breakfast. In each restaurant, I asked for the check as soon as possible so that we were paid up and ready to head into the park before the official opening time.
We did Tusker House our first day. The food and character interaction was great. Yummy. And I knew (from researching here) to ask a CM to take a picture of us w/Donald with my camera so we didn't have to buy the expensive "professional" one.

Would absolutely do this again. Loved the whole experience. And here is my dh walking to the safari after breakfast. We were able to get onto the ride about 5 minutes before the park officially opened. Walked right on well ahead of the huge crowds who arrived later:
We did Hollywood and Vine the next day. The food was fine. IHOP type food which is what I was expecting. Hot coffee, eggs, bacon and waffles. I wasn't expecting anything fancy. My young kids loved the characters here. And we were able to get to the front of the line as the hordes of people headed to TSM and Jedi Training (Star Tours wasn't opened yet). We couldn't walk ahead of the CMs but we joined them as the hordes approached, so we were first. We split up and by a little after 9, I had our TSM fastpasses and DH had the kids signed up for Jedi Training. Would do this again possibly - just to get into the park early and aviod pressing thru the crazy TSM crowd. Here is my daughter dancing to breakfast in the empty park:
We did Cinderella's Castle on our 4th day. It was such a magical experience for my dd that I hardly remember what I ate. It really was a once in a lifetime thing. Don't know if we would do it again b/c it can't possibly ever be as magical for her (and the rest of us) as it was the first time she ever entered the Magic Kingdom, walked up an almost empty street and right into the castle to see princesses. She was in awe the whole time. After breakfast, we waited with other breakfast eaters at a rope next to the carousel (and got a photo with the Fairy Godmother who walked out before rope drop). We were released from that rope behind the castle at the same time the people in the front of the park were released. Here we are on the carousel. At this point, I already had fast passes to Peter Pan, and we were the first and only family on the carousel! It was amazing! All the other breakfast families ran to Dumbo first. DD was ready to burst from happiness. Breakfast in the castle. The Fairy Godmother complimenting her dress and then a ride alone on the carousel. There was some pixie dust flying over her that morning for sure.
So, as you can tell, I'm a big fan of early park breakfasts. My kids wake up every day before 6am - so for us they didn't even seem like early breakfasts.

Have a great trip!