I LIKE California Adventure, and if you haven't been there before, I think you can easily spend a day there! But some of it depends on the age of your kids and what you all enjoy doing. There's "a bug's land" for younger kids, but apart from that area, Monster's Inc. and Playhouse Disney, there's not as much for the younger set. For older kids who enjoy thrill rides, there's Tower of Terror, California Screamin', and Grizzly Rapids, not to mention Mulholland Madness, Soarin', and the Sun Wheel, but if you go to a theme park to ride rides, there's not as many at DCA as at DL.
But there's the Aladdin show, which is fantastic, and Golden Dreams is an interesting movie, and I can spend a long time in the Animation Building, between Turtle Talk, Drawn to Animation, the Sorcerer's Workshop, and just sitting inside watching the movie clips. The "tortilla factory" and "Boudin Bakery" tours are a little cheesy, but you DO get free samples.
I enjoy doing ALL of that, so DCA is NOT a "half day" park for me - while I don't want to ride the "carnival" type rides in the Paradise Pier area over and over again, I think they are fun to do once.
I think a lot of people go to DCA with the wrong expectations - DCA is NOT Disneyland and it's NOT Magic Kingdom - it's more like Disney-MGM Studios with a little Epcot thrown in.
Laura