I've been using John MacArthur's workbooks for a few years now both personally and in small group. There's lots of great information in the books and you are encouraged to really dig and get involved. As with any Bible study you're going to get out what you put into it.
John is an excellent teacher. The books are great in that they give information but not only that; they encourage us to search our hearts to discover what the truth there is and how it relates to God's truth. John is a great encourager to get the student to seek to do God's will with a lot more sincerity and truth.
Generally good format with scripture text and supporting notes; we are using in a men's bible study, and are into the third lesson, which includes the entire Sermon on the Mount, Matt 5-7. This turns out to be far too important and way too much material for a single lesson, so we won't be finishing in 12 weeks, which is fine. MacArthur's notes are ok, but there are verses that I wish he had commented on, but didn't. Overall, good way to study Matt, does include some of the parallels from the other gospels for comparison.
My wife and I and our two teenage daughters have nearly finished this study on the book of Matthew. MacArthur has done an outstanding job organizing and presenting the gospel of Matthew. The questions are on point and great for discussion. Sometimes they are a bit confusing and open ended but we found that we often times each interpret these questions differently allowing for more depth in our discussions. I didn't give the book 5 stars because it uses the NKJV which I'm not particularly impressed with. I would have preferred the NASB for New Testament studying purposes (we just use our own bibles rather than the text provided). Overall the book has been extremely helpful and well worth the cost. My expectation is that we will use this series for our future studies.
I wanted a Bible study that would actually explain the background and meanings of words that aren't obvious from the surface. This book includes that insight alongside the actual scripture (I'd prefer NIV, but that's just my preference.) and contains thought-provoking questions (although I'd like a suggested-answer guide in the back). There have been a few instances where I wished the book would explain a section of scripture, and I have to turn to my study bible or another book (Barclay?) about Matthew, but I like this book. For a group, it's nice that each chapter starts with a casual-type, related, conversational question and then delves into the scripture. We read the scripture during the lesson, and from that perspective, there is too much packed in, so we don't finish a chapter in an hour.