Hi, this is my first post, too.
I have a DS in first grade as well. We do AAS afterschool. For awhile, I was reteaching him too, but that was a confidence booster for him. He loved playing with the tiles and using the white board. Now he has advanced past the school's teaching, and does very well on his pretests for spelling. AAS has also helped him build his dictation skills, which was important to me. I just bought book 2 and am glad we are sticking with AAS. I like its vision.
We try to do one AAS lesson a week, and I include his school's spelling words in there, too. He spells words with the tiles one day. Then he spells them with the dry erase markers. Then he does the AAS dictation words. It works well for us. Even though it is a bit of an abbreviated version (15 minutes, 3 days a week), it is worth it. In the summer and breaks we will do more.