My children and I are slowly assimilating the HOD materials into our lives. My 7 and 9 year old are doing particularly well with the materials from Beyond and Bigger. My 11 yo is having some challenges with Preparing. He likes to work independently and can work independently, BUT it bothers him that so many of the instructions are written to the "teacher." By the time we have our one on one time to go over his work and tackle a few items together, he's a little discouraged that he hasn't been able to do as much as he would like - particularly Bible. And I think the "teacher wording" seems youngish to him.
We're working on that, though, and I'll let you know how we ultimately tweak things to make it work for all of us. The big hits so far have been Benjamin West, Beyond Bible with scripture memory, American Pioneers and Patriots and Rod and Staff. Oh, and the True Story of Noah's Ark. My 11 yo was particularly pleased that the Draw and Write through History had the ark depicted correctly. 
I'm not using the CD of hymns, but am inserting my own. I have a fairly good knowledge of hymn repertoire, and there are so many that fit "perfectly" with the lessons in Beyond. I'll share my list once its somewhat complete. Next week we'll work our 4 year old and LHTH into our rotation. She's very excited. On a more personal note I'm really pleased with the Science for all the levels that I'm using AND I'm very pleased with what we're doing with literature and read-alouds. These were 2 main motivators for my switching to HOD and they've been right on. 