The studies are good in essence, but are a little too long for a weekly hour and half bible study group that wants to include a serious prayer time, unless you don't discuss anything and just roar on through, which is obviously not conducive to helping each other grow in our understanding and faith. The studies are faithful in their content, but being written back in 2003, the examples are a little dated eg: referencing the Sydney Olympics (24 years ago), and the National Gun Amnesty (28 years ago). So they could use some updated examples.
It's really hard to find studies that strike a balance of being: 1. a suitable length, 2. meaty enough for mature Christians to think through, 3. not so meaty that you have to have gone to bible college to understand them, and 4. are written with a local (Australian) audience in mind. These studies match that expectation at times, but (I've found) are often are looking for a "God", "Jesus", type simple answer. Not that that's necessarily bad, but those answers can feel a bit forced at times - like you trip over yourself thinking "it can't be that easy, they must be looking for something else".
All that said, there are far worse offerings out there, and as I said at the beginning, they are faithful to the Word, and most of the guiding narrative is really very good. So, knowing the studies' limitations, you can always take some time in your weekly prep to alter questions or examples that might suit your group and time allowances better.