We did a (very expensive) summer of LMB with my now 11 yo DS who has a high functioning autism diagnosis (he is in a regular classroom). Like your son, his decoding skills were fine (above grade level) but comprehension was poor (10th percentile). Unfortunately he made no gains in comprehension with this therapy. I looked around pretty hard at various options and my understanding is there is little that works GREAT for comprehension. It is just a tough nut to crack for PDD/ASD kids. Mimio/headsprout has an online product for reading comprehension that we liked and was vastly cheaper. Have you looked into that ? My son's comprehension has gradually improved but it's still below grade level and an area of concern.
