Oh Boy, what a question! We are also West-Coasters, up North, but still much closer to DL than WDW. We loved WDW - it is a WORLD unto it's own - you get on that bus from the airport and that's it, Disney takes over. We love Disneyland, too, but it is much smaller. The 'resorts' are nice DIsney hotels, you can't walk them for an hour to get from one end to the other. There is nothing to eat at Disneyland compared to WDW, just a couple of decent places. After WDW, we wouldn't ever dream of going off-site to eat, but at Disneyland, we eat a bit at DTD and a little in one of the two parks and Mimi's (by Howard Johnson's) or maybe (big maybe) a fast food joint across the street from DL. Some may argue this, but no way I could spend less than three days in DL; five is about right if you want to do pretty much everything in both parks and the stuff you really like twice or more (Screamin', nine times in three days...) Depending on time of year, yes it can get busy at DL, but nothing like the wait times in WDW (in my very limited experience). Love TSMM, but could not believe how quickly the FP system was used up - we got there 1/2 hour before regular opening and still our FP were for 1:30 that afternoon and the line up was 1 1/2 hours long already!!! In California Adventure, if you get there at opening, you probably wait 1/2 hour and (I might be wrong, it's been three years) there is NO FP for TSMM. The line can get longer later, but usually reasonable at opening. DLs It's a Small World is much more impressive from outside; we have Matterhorn and Indy (similar to Dinosaur, I like Indy better but many disagree), our Pirates is better (drop), submarine ride, our Autopia (IMO) is much better than speedway. We have 'Bugs Land', we'll have Cars Land, Screamin', Little Mermaid, World of Color (I haven't seen but I sure want to!) Fantasmic is supposedly better in DL (I haven't seen it enough to really compare, but most who have would say so) but I did enjoy the seating in WDW vs. standing in DL. Tower of Terror is better in WDW I think; no Rockin' Roller Coaster, no Philharmagic (which I loved and wish they had here), I like our Animation Academy better, no 'Hollywood Studios' here (and I loved the Walt DIsney story), no Animal Kingdom (and I think Kali is longer than Grizzley, but I could be wrong), no Everest, no Safari or animal exhibits. No Epcot - nothing like Epcot, nothing can compare! Soarin' in California Adventure (I think) has a nicer queue. California Adventure has some nice 'classic fair' rides - Silly Symphony Swings, Mickey's Ferris Wheel, Golden Zepher (might have the names wrong, sorry!) Goofy's Sky School is a mouse-coaster, it's fun, but I didn't get to go on the one in Dinoland USA (it was closed, might still be?) I think California Adventure may have (hopefully) gotten rid of it's 'Carny games', not sure?
Downtown Disney is a ten minute walk maybe from end to end; one of the nicest things about Calfornia's Disney is that it is close to 'itself', you literally walk across the pavillion to the other park and turn left (or right, depending on where you're coming from) to get to DTD. It's small, but then you don't waste an hour waiting on and transporting to another park or resort or area. We will (according to DH) never stay any further than across the street at Disneyland; there are plenty of hotels to chose from and though they're not Disney, they all have comfy beds to rest in after a long day in the parks. Haven't stayed at Howard Johnson's but I hear they have one of the best pool areas overall for kids off-site if that's a priority; most just have a rectangle! Our last hotel was the Carousel and my husband paced it out at 110 steps from our room to the crosswalk to Disneyland and swore we'd never stay further away again after that trip (and I went - 'Woo Hoo! We're gonna have at least one more trip here!' at that time; pretty much converted him over totally at this point )
You HAVE to do it at least once, just so you can say you did it and know what the heck everyone's referring to. Even though it'll feel 'off' compared to Magic Kingdom (the layout is just a little different beyond Main Street), you'll still enjoy it and get something out of it. I don't know that I could pick a favorite if I had to between the two coasts (and man do people ask!) because they are such different experiences. Have fun and let us know what you think once you have been!