Trevor finished his
Spectrum Writing book last week. I figured he'd be done with it early, and I've been waiting to jump back in to Shurley.
I like Spectrum Writing just fine; this is the fifth year that one of my kids has used it. But as soon as I open up that Shurley book, I get excited all over again. (I obviously don't get out quite enough.)
Shurley is pretty intense for elementary grammar. It is written to rely a lot on memorization of jingles and a specific order of questions to determine different parts of grammar within a sentence. The Level 5 book is full of all kinds of fun things: predicate nouns, indirect objects, antecedents, adverb exceptions. ("Fun" meaning I have no idea what these things are.) And to be honest, while I learned most of these three years ago with Holly, I can't tell you today what any of that means.

We were first introduced to Shurley when Holly attended the part time school. I didn't understand any of it, but Holly took to it like a duck to water. (Sorry, Holly!) She was taught Shurley there for 2nd and 3rd grade. When we withdrew her from the school, we tried two other grammar programs, both of which were huge flops AND colossal wastes of time. By the time 5th grade rolled around, I took the plunge and went back to Shurley.
It's expensive compared to other grammar choices. It's time intensive, and the teacher needs to have a good grasp of what's being taught. If not the teacher, then the student--even though Holly had not used it for a year, and had skipped a level, she took off like she had never stopped. This was helpful to me, since I'd never taught it.
It worked so well that I bought Level 2 for Trevor a few months later, and he did Level 3 last year. Since I already had the Level 5 Teacher's Manual,
and since we're doing Latin this year for grammar,
and since I didn't want to spend money on Level 4, Trevor's jumping back into Shurley Level 5.
In addition to teaching grammar, the lessons cover punctuation/capitalization rules, usage, vocabulary and dictionary practice, and writing lessons. I am not a big fan of Shurley's writing, much preferring Spectrum and IEW. But the lessons are easy to fit to my family; we've never used the jingle CD; Holly's never done vocabulary and Trevor's not doing it this year; neither have used the writing portion. (One more ding, really, against it, because of the cost.) But it's worked best for us, and I really am glad to be using it again.