Vinyl and wood are the two most common privacy fences we build, and homeowners ask us to compare them on almost every estimate. Neither is better across the board. They just age differently.
Wood costs less up front and has a warmth vinyl can't fully match. You can repair it one board at a time and stain it any color. The tradeoff is maintenance: inland San Diego sun grays and dries wood quickly, so plan on cleaning and re-staining every few years to keep boards from cracking and cupping.
Vinyl costs more to install but asks almost nothing afterward. It doesn't rot, doesn't attract termites, and never needs paint. A rinse with a hose keeps it looking new. White and tan vinyl both pair well with stucco homes, and ranch-rail vinyl is popular on larger lots in Ramona and Poway.
Whichever you pick, the posts matter most. A privacy fence acts like a sail in Santa Ana winds, so posts need proper depth and concrete footings. That part of the install is what decides whether your fence is still straight in ten years, regardless of the material on top.