My almost 7 y.o. has done very well w/ this curriculum. We started w/ 2 1/2. She's moving thru the books without too much difficulty. She also has her favorite sections. We also do Beyond the Code in conjunction w/ this series. We also do Spectrum language 2 as well.
Explode the Code 3 1/2 contains practice with long vowel sounds and digraphs (such as sh and th). The pictures are good; even my student who is an English language learner knew what most of them were. I would have liked more practice with -y as a vowel. Overall, it is a good phonics practice book.
There are many curriculums, workbooks etc. that have come and gone, but we have used ETC from the beginning and have continued with it with each child. It is fun and goes along with whatever Phonics program we have done. My dtr. finished book 3, but still needs more practice in the skills, so 3 1/2 is great!
My 6 yr old loves working through his Explode the Code workbook. The instructions are simple and he can work on his own, although I usually sit with him to make sure that he doesn't rush through the pages. He loves to read the questions because they are fun and silly, although they are very thoughtfully constructed, to incorporate the right words for teaching a certain phonics skill. This is our first experience with Explode the Code, and it has been great.