Updated Review: Feb 2021
Still using this textbook for my Middle School Class. Thoroughly fed-up with it. The exercises given in the textbook (and the workbook too, though less often) are very inintuitive. Grammatical concepts are not introduced in an ideal order (no reason to learn the passive voice before the imperfect tense, and it's a very difficult concept for 6th graders to master - suddenly the subject isn't doing the action anymore!).
There is an entire section spent on the irregular noun vis, but this noun is rarely used again in the textbook. Which is part of another problem - the vocabulary introduced isn't used consistently, and often isn't common (why do we learn gremium in Chapter 7?)
I would rather craft my own curriculum for middle school based on Wheelock. It wouldn't be any more difficult, since I'm already creating my own exercises, and modifying the presentation of the syntax and grammar presented in the textbook.
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My opinion of this text is colored by the fact that I am teaching 6th and 7th grade, and this is not a middle-school Latin textbook.
It's ... alright. It doesn't do enough to distinguish itself from the old standby, Wheelock's, to really justify its existence. I can't imagine preferring it to Wheelock, and I think the latter is structured far better than this is.
It's also simply not good for teaching middle school Latin. But probably slightly better than Wheelock in this regard.