Well, as far as breakfast buffets go, we have been to both HRH (The Kitchen) and RPR (Islands), and we love them both. Basically, the same thing at each place. In fact, it is hard to think of a breakfast food not represented on the buffets. They run just over $20 per person, and include all drinks. Omelette stations, breakfast meats, biscuits and gravy, oatmeal and grits, sweets (french toast/pancakes), potatoes, fruit, yogurt, doughnuts/pastries, etc. We load up on this in the morning, have some snacks in the parks (always room left for the Big Pink and some Butterbeer), then eat dinner at CityWalk/Hotels/Favorite Park Restaurants.
For a family of 4 - I budget between $100 - $120 based on the waiter/waitress. As with any restaurant - some are great and some are just OK. Our family tends to overdo the breakfast drinks (OJ/Coffee/Choc Milk), and that matters to us. I will gladly throw in an extra $20 if our glasses never empty. Plus, if you go daily like we do on an 8 night stay - the good ones tend to remember you, and that is a great feeling.
I do believe PBH has basically the same thing at Trattoria, but we have never eaten there. I know RPR has a few morning with character interactions - its the same buffet, plus a few dollars more. I know they are teenagers - but I would recommend - all of the characters are very fun!