I'm not sure if I placed them correctly this year (CTC with the extension for the older boy), but because it was our trial year, I wanted to do everything together. I knew there was going to be quite a learning curve for us as prior to this year all of our subjects were heavily teacher-directed.
Regarding Grammar / English:
Building with Diligence (youngest)
Following the Plan (eldest)
These texts have not been difficult for the boys and much has been a review, but a good review at that. All other recommended books have been wonderful. I do notice that my boys consistently do not remember to carry over correct punctuation, capitalization, etc. Their writing is sloppy, especially on the notebook pages where there are no lines to write upon. (I should mention that my eldest has a movement disorder so this would definitely play into account here, but he still could do better.) I feel like a nag when I correct their work, and this is a tender point for all involved. I've apologized many a time for losing my patience.

Regarding DITHR and other reading material:
My youngest child is the Level 4-5 workbook with the Level 3 book pack. He has difficulty reading quickly, but his comprehension is *okay* (not great, not horrid). I've had to help him with his reading material (I read a paragraph or a page and then he reads a paragraph or a page) whether it be for DITHR or science or history. Lately he has seemed to improve and can read more independently. (The Bird's of the Air book is easier for him than the Apologia text we had been using earlier in the year.) Maybe he's improving! I KNOW that he's really impressed me with his progress with spelling this past year or two.
My eldest has absolutely no troubles reading the Level 7/8 books. His speed, comprehension, and memory are excellent.
Written / Oral Narrations, Copy Work, Dictations:
My youngest needs to be coached heavily for oral narrations. Regarding the written narrations, he needs help every step of the way...finding the answer in the book, writing the answer (with correct punctuation, etc.), etc. This has been frustrating for both mom and student alike.
My eldest has no difficulty in talking for oral narrations! He could use refinement in the area of not starting each sentence with the same word, etc. His written narrations are beautifully written concerning content and language use but lack in the area of consistently correct grammar and neatness.
Both boys at first didn't seem to notice their errors when correcting their copy work or dictations, but this seems to be improving.
Math:
We've used RightStart Math from the beginning. The subject of math is difficult for my youngest. I would consider exploring Singapore Math next year as we will have finished RightStart Level E with him. (I will not be using RightStart's geometry for him which is the recommended next step along with VideoText Algebra.)
My eldest started VideoText Algebra in 6th grade. We are still working through that, taking it slowly. We did for a time do RightStart Geometry along with that but have since decided to put that aside for now (or potentially permanently). Since he started this in younger years, do I grade it for high school credit? I'd hate to do that since his grades (and we haven't really been grading, just checking for understanding) certainly don't measure up to what they should be for an older high school age student. I'm open to starting something different with him. We used VideoText because that was what was recommended by RightStart and we were given Modules A, B, and C for free. We are currently working in Module C and would have to purchase every module that follows. I should mention that it is not unusual for him to get 50% of his problems wrong in math (and then we do the extra problems / quizzes provided). This is not due to him not understanding the concept, but because he makes silly errors. I'm not sure that he is retaining this information though, but only "parroting" back the concepts in a rote manner based upon the most current lesson.
In math, and everything else concerning the eldest, things come very easily. YET, he does not show enough maturity to remember to follow through. Even though he reads quickly and grasps content, he is consistently the last one done for the day. He daydreams, complains and whines, turns in sub-par work (ironically due to rushing through his work), and is easily distracted. Remember the nagging comment above? This boy is my mover, and if he'd gone to an institutional school, I'm sure would have been labeled ADHD.
It scares me to think that we might have to run separate guides in the future, but from reading the board, it seems that several others here have done this successfully. I, however, am not Wonder Woman as so many, many homeschooling moms prove to be. I struggle with depression and die to myself daily to teach my boys, and imperfectly at that. Additionally, I fancy the idea of my eldest working though all of the high school guides which would mean that for his eighth grade year next year, he should jump to MTMM. I understand this thinking isn't the best either if the level isn't the best fit for the child, however.
Well, if you're still reading, congratulations! Thank you for any suggestions in helping me guide my children through a successful school career.