Whitney,
We have used both. I have two children using CLE math and my DS8 does very well with the spiral format. For what it is worth I absolutely DO NOT like the LA. I put my CLE math boy in LA2 and dropped it after 2 LUs and ran back into the arms of R&S English. I find the presentation of concepts in CLE random and I do not like the worksheet feel. I would rather practice capitalization, punctuation, etc. in the context of copy work. If you skip,the penmanship and spelling you are not left with much. Also, I found myself teaching CLE just like I teach R&S

and I wanted to chuck the LUs and pull out the whiteboard. I find R&S to be much more flexible to teach because I can speed up, condense, or slow down as needed.
I firmly believe that retention will come. R&S builds carefully and thoroughly. You review concepts in each level taking it a bit deeper each year. Beginning with English 3 there is a daily oral review. I have found it to be highly effective in building retention and fluency with the concepts. In addition, you can purchase laminated charts for the different levels that have POS, diagramming helps, etc. at a glance. You can utilize the worksheets also. I find it effective to ask my student to use a worksheet from a topic we studied in the past. I pull them out on busy days or when I think he needs to revisit a topic. Personally, I like using the tests beginning with English 4 as a gauge for retention.
One last reminder is that English skills learned in R&S are supportive skills for,composition. HOD gives you many opportunities to apply the skills learned in writing across the curriculum.
