To answer your question er, the SD Unified enrollment options catalogue lays everything out. You have to go to their website to download it. The short story is that 3 out of the 4 programs actually give priority to the lowest achievers. Once you have transferred, the district’s continuity policy keeps you at that school (if you want) so no need to re-apply. The only students given priority over the lowest achievers are siblings of continuity students, regardless of performance.
There are plenty of local 92037 kids to fill those schools. The 2010 census says there are about 12,000 school-age kids in 92037. That is actually an increase over the 2000 census figures so the school-age population is rising, not falling. The fact is that many opt for private schools and that leaves enough space open for lots of transfers.
From what I have seen regarding CV vs LJ the data is what it is. At the middle and high school level (haven’t had time to look at all elementaries but probably there too):
CV – higher test scores, almost entirely local students, minimal free lunches, higher percentage of educated parents (college/grad)
LJ – lower test scores, substantial non-local students, substantial free lunches, lower percentage of educated parents.
CV has overcrowding issues at a few schools that I think exceed such issues in LJ. CV has a significant and growing Asian enrollment. LJ has a significant Hispanic enrollment.
What people do with these facts, how they interpret them and so on, is up to them. These are just the facts m’am.