tinkerbellnut - you will be there during our DIS meet!

Look for people with lime green ribbons.
I love both WDW and DL/DCA. The biggest advantage to Disneyland over Disney World is that everything is right there - you do not have to have a car or use Disney transportation to get where you want to go. If you stay onsite, you will walk right through Downtown Disney to get to the main park entrances, and they did an incredible job! If you stay offsite, you can still be so close that you can easily walk it - maybe even closer than onsite. You will have very little of the greenbelt that you are used to at WDW, it is indeed a very urban environment.
DCA is a cross between MGM Studios and a World-Showcase-like California exhibit. Ther are some amazingly good rides there - the California Screamin' Coaster is almost as much fun as RnR, and the Soaring Over California ride is a wonderful simulation of hang-gliding. I didn't try the Grizzly Rapids water ride, but my family tells me it is better than Kali River Rapids by far.
Disneyland itself is the original, and a few rides there are far better than WDW - Small World is really worth seeing, and Pirates of the Carribean is much, much better at DL. The Indiana Jones ride is awesome - like Dinosaur in technology, but much better theming. If you are with little kids, they will love Fantasyland at Disneyland - several more wonderful kid rides there than they have at WDW.
Hope we see you there, and that you have a great time!