What a great response you've received already from the pp, and I have more of the same to share from my experience.
I used Spelling Power for years in teaching in ps before using HOD's dictation in teaching my own dc. How I wished I'd known about dictation back when I was teaching ps!!! Dictation is easier to implement, carries over more into dc's own writing, and results in better retention of how to spell words than anything else I have ever used. I think the secret is twofold. First, HOD's dictation follows a purposeful progression that builds incrementally upon itself from year to year, from guide to guide - this is far different from doing dictation from random passages. Second, dictation teaches dc to spell correctly within the context of writing sentences - this is far different from studying a list of words each day. My oldest ds had speech difficulties as a child, and spelling was not his thing. His spelling scores on standardized testing have risen from below average to far above average over the years, and I attribute it 100% to dictation. On the flip side, my middle ds was an excellent speller from the start, and his spelling continues to improve anyway! He is flying through his dictation passages in PHFHG, and his spelling in his own writing is excellent. Yeah!
As far as R & S English, chillin'inandover said it well already...
...I also use Rod and Staff for grammar and my son enjoys the quick lessons and his state required standardized scores were in the 98% in language arts so he has the necessary skills. I have used many other grammar programs but I have enjoyed the Rod & Staff the most for cost, ease, and interest. I have used Rod & Staff 2, 3, and now 4 for grammar- the skills have progressed at a good pace and the review has been adequate...
I'll add to this that R & S English 5 continues to help my ds progress well, and it is teaching many excellent writing and speaking skills as well. R & S English covers everything so well - how to give an oral report, how to outline from several resources, how to write a good paragraph with unity and order, what order and with what manners to introduce people to one another, how to use references such as phonebooks/dictionaries/encyclopedias, etc. It is truly an amazing English program that covers all of the bases well - and it's Christian too, so no worrying about inappropriate sentences (i.e. Who will you take to the prom this year? as another grammar program I saw used for a diagramming exercise). Finally, HOD's recommendation of doing 2/3 of R & S English orally and having dc write the rest makes it clip along at a good pace, so it is manageable to do year after year. Oh, one other tip - it's important to do the 5 oral review questions in the R & S English Teacher's book - I forgot this for a bit, and it really is important to do as it is one more way the program works to instill good retention from day to day, year to year! HTH!
In Christ,
Julie