I also recommend H&V, particularly with the ages of OP's children. We ate there for breakfast twice this year - in April and October. The food is fine, little ones may really enjoy the characters and the CMs are really cheerful. Our 5-year-old really liked the atmosphere and characters, and our older boys initially liked the idea of getting into the park early.
Just a planning note, based on our experience in October. We had a 8am ADR for a posted 9am opening. At the time, there was no "rope drop" at DHS and they let guests through the gate gradually. I think they let guests in at least 20 minutes before opening, from what I could see out the H&V window. I read about this before our trip, but was surprised by the significant impact on our plans. When we were finished with breakfast (before 9am "opening") there were tons of guests already in the park and the standby line for TSM was really long. That had a ripple effect on our plan for the morning. In the end, our early H&V ADR worked against us, given the opening procedures at the time. I'm not sure how DHS is currently operating at opening time, but that's something to watch if the purpose of your ADR is to get going early!