In general a degree from a UC will be more valued than one from a Cal State, but SJSU has a good rep for CS because of its proximity to Silicon Valley. Jan Khoum, founder of Whatsapp, went to SJSU. In terms of overall reputation, UCD probably has a better overall reputation than UCI or SJSU.
In terms of location, SJSU is located near San Jose. The entire peninsular between San Francisco and San Jose is just paradise IMO. I’d move back there in a heartbeat if I were rich. Perfect weather, beautiful palm trees everywhere, close to the ocean.
Davis is just outside of Sacramento, not sure how easy it is to get to Sacramento. Sacramento is also a nice city, just not SF. It probably gets very warm there by May.
SJ weather is beautiful year round. Irvine is spread out, hard to get around without a car. Public transportation is really bad in SoCal. In San Jose you can get to SF easily via BART.
Tough choices. Perhaps you should check out the ranking of the CS department between these 3 then decide.