DWCAP, The 5500 housing units in the canyon in south MM will all be multifamily units. You can go here for info. Read their meeting minutes. The 100+ house at the corner of Camino Santa Fe and calle Cristobal, is zoned as SFR for the South of Calle Cristobal and East of Camino Santa Fe corner. The north of Calle Cristobal is zoned as twin homes. This is the same for the South of Sorrento Valley Blvd and West of Camino Santa Fe.
I don’t think the 92121 vs 92126 zip code matter as much as how new the house is and how big it is. It seems like people like the 92121 houses more because it’s new and bigger and the area look cleaner. Both area goes to the same school, so, other than size & age, there’s no real difference.