I agree completely with Daannzzz,
there's a huge difference in size and theme....but the Magic Kingdom (
Disneyland Park) in California is, in my opinion, better in a lot of ways than at WDW. (Please, no flames)
Disneyland has a certain charm and California Adventure is a relaxing change of pace with at least one ride you won't find (yet) in Florida...Soarin Over California...one of our favorites. I love the pier area at CA also.
DL can be done in a lot less time than WDW, but 3 days is the absolute minimum, I think.
I also love walking through Disneyland knowing that this was Walt's dream...his world. I love going up to the galllery, knowing that he lived in there, and trying to imagine what he was doing, and what he was thinking about. Guess I'm kinda weird, but my heart belongs to DL. (Again, no flames...) I love WDW for a long, huge vacation, and for the fact that the cruise ships are there, but DL is always worth going to, for any Disney fan.