While more professors means more research opportunities, it also means more competition for those opportunities. However, San Diego, much like the Bay Area, is a hub for technology startups, and an engineering degree from UCSD is highly respected in both regions. Your first sentence summed it up: what school other people like more shouldn’t affect your decision–if you liked the UCSD vibe, you’ll fit right in here.
I don’t know what you’d be missing out on–maybe huge frat parties (the ones I’ve been to here are pretty fun, but definitely not LA-scale ragers). School spirit is kinda lacking (that’s getting gradually better though). Triton Eye is not a thing (Berkeley Goggles still is). There’s also no real college town, which could be a turnoff; La Jolla is kinda sleepy and San Diego/Pacific Beach are generally more fun once you’re 21. San Diego has 3 of the country’s top beaches though (at #6 La Jolla Cove beats many Hawaiian hotspots).
With regard to academics, though, I don’t see how you’d be missing out. The difference between Jacobs and Samueli-UCLA is negligible, and if you want an engineering degree then Berkeley probably isn’t your best bet now. Good luck with your decision!