While I have completed a good 30 or so hours of Rosetta Stone and am deep in the level two area, I still haven't the foggiest on grammar or how to string a series of words together to form a sentence. While it is true I can point at a picture of a green apple and tell you what it is in German, I wasn't able to say, can I have a green apple and so on. Sure I had a step up going into this as a knew a great deal of words I still had no idea how they worked. Paul Noble uses a simple approach that I practice while I run and walk around in my day and for the first time, I can actually speak German. Can I move there today and fit right in. No, but can I say simple sentences that I couldn't before. Yes. Have I been able to form sentences when I wanted to answer someone. Yes. So, overall, to me, there is not a better learning solution than this.
I can understand someone's frustration after completing part two and feeling they can take on the world of German speakers. Thus, part 2 feels like a review. But practice makes perfect and while it is part on only slightly more advanced it is essentially to the learning of a second language. Or, just do the last half of part one again. Same thing.