I'll share my two cents as we used
DVC pts. for a 5 night stay at the GCHotel last month... It rivals the ambiance of the Wilderness Lodge, and it's location couldn't be better. Just go outside and you're in the park, literally!
You may notice "less" commercialism at DL (less is a relevent term when it comes to Disney)...***the only ride at DL Magic Kingdom that exits into a gift shop is Small World... Compare that to WDW MK and basically every ride exits right into a gift shop.
The improvements at the Disneyland Resort have been amazing... They have really made it a destination location worthy of more than just a day or two. The Magic Kingdom certainly reflects the nostalgia of Walt's original dream.
We were even able to ride (paddle) the Davy Crockett Canoes (first time we'd seen them open at either park!) And the Indiana Jones Ride at DL is probably the best ride at any Disney park.
DL attracts its share of day trippers vs. the extended visitors to Orlando. If you can visit during the week, especially when school's IN session, you'll notice a considerable drop off of crowds and will probably enjoy your visit even more.
Calif Adventure is a good park. It has some great attractions (Soaring over Calif., Grizzly River Rapids, Sun Wheel, etc.). It's like a small sampling of MGM, Epcot, and amusement park. It's still in development and should only get better as they add more attractions.
Since we travel from the east coast, we've done other Calif. attractions after an extended stay at DL. (San Diego once, San Fran once, and this last time used DVC points through the Concierge Collection at Shutters on the Beach, Santa Monica for the beach scene!).
In some respects, trips to DL are more relaxing since there's less to see and do vs. WDW... and the weather is practically perfect everyday (no pesky afternoon thunderstorms, although the distant smog isn't too appealing). Because of the lack of rain, the Teacups, Alice's adventure, and Small World have more open air access and even Main Street doesn't have as many canopies which gives it a more open feel.