Personally, I think the structure based acquisition setting would not be very good for an ELL. The drills would not really allow for student creativity and may dissuade the ELL from trying to use their knowledge in class. This approach seemed the most 'old school' to me, erego, I immediately disliked it.
From chapter 6 I liked the "Teach what is teachable" section. I mean, it just makes sense; if students are unable or unwilling to learn it is useless to try and teach that particular lesson. It is kind of like the L+1 idea, teach them just beyond what they currently know and the teaching will likely be successful.