I think different schools and districts emphasize different skills. However, it would be solid mid to late K level for our school. The issue is really how much your DS can improve by August and where you are comfortable for him to fall within his class. For our school, tracking starts in 1st grade so he would not be at the level of the top performing kids if placed in the pre-GT 1st grade. While reading comprehension is important, the students in our school are judged on their written output so lagging writing skills could jeopardize GT placement. That's not meant to imply that your DS would not thrive in 1st grade because chances are that he will make a substantial leap between now and August.