In 4S Ranch, I have not had any problem getting my kids into the school-sponsored afterschool program nor the summer program at Stone Ranch. I haven’t heard of major problems at any of the other schools, either. For the Poway Unified School District, the after school and summer program is called “ESS” — “Extended School Services.” I enroll my daughter in ESS and then pay for a few additional “enrichment” classes offered through FitKids America or KidzTyme. These classes are onsite and the majority of kids taking them are ESS students, although some other students take them as well. My daughter has taken classes ranching from Reading Enrichment to Chess to Soccer to Hip Hop Dance. If they are not taking these enrichment classes, ESS has various activities for them as well.
Another popular afterschool option among our acquaintances is “All Star Academy” on Thornmint Road. They seem to have a more academic focus and have options like Chinese language, Spanish, etc. They transport kids via a van from several local schools.
On the north side, there has sometimes been overcrowding for school enrollment at Monterey Ridge. I think there are some old threads here on that issue. I didn’t hear of any one who didn’t get in last year, so it may be improving.
Design 39 (D39) may also have more applicants than spaces. You have a much higher chance of getting in if you live in Del Sur vs if you live in 4S Ranch, as the slots are allotted based on Mello Roos. I have heard that some parents like the freedom/open concept of this school and some do not, so this may or may not matter to you.