We moved to Oahu in june 2013 via the army. For us it was a huge pay increase plus we "found" mmm just before we moved so we also downsized (from 2400 sq ft to 1000 sq ft) and sold a car, now a one car family. I've never been to CA so i can't compare. We are also a family of 4 so i don't know much about the single scene.
We live in a new fancypants housing community (gated, pool, walk to beach) not my choice but i want to stay married ;) and it's not that far out of what i budgeted. We live in the desert part of the island which means not much rain and endless sun, but it's balls hot. I have some of the best neighbors, my friends here are awesome!!!! My kids aren't school aged.
I'd say if you come here then live near your work. Commuting here sucks, unless you can get an opposit commute.
It is expensive..but you're on an island far from any major "mainland" There are a lot of tourists (depends on where you live/frequent) and you may get many visitors! We have company every month, sometimes 2 or 3 different guests in one month. That is probably our biggest expense. They all want to see this or that and taste this or that. Most things we do are free, but gas to get there, extra groceries, etc etc..it ads up.
Also, depends on the individual, i was discriminated against a bit (blond haired army wife) even after "studying" culture differences and 'how not to offend locals' I still felt it. It's better now that i can pronounce the name of my street correctly ;)
Things i love, besides the obvious...
Never getting dressed up again. Island time. Never wearing shoes. Beach hair is "in." Island time. Suntans. Free hair highlights. Relaxed kid image (in other words, nobody snubs their nose at you when your kid starts running around screaming...they jump in the fun.) Food trucks. Island time.
Good luck!