I think it's difficult to compare the two, because they were built with different purposes in mind.
Disneyland was built as a 1-2 day destination, WDW was built as a resort and intended for guests to stay for a week or more at a time. When Disneyland was built they didn't even have their own hotel. The Grand Californian is the only hotel at DL that was built by Disney, the other two were already there and were purchased (Paradise Pier was the Pan Pacific hotel). If you're going to compare them then you have to compare the individual components - DL proper (without DCA) with MK at WDW, and DCA probably with MGM or Epcot.
I personally love DL. I love the coziness of it. I love the fact that Walt walked down the streets and corridors daily. I love sitting in New Orlean's Square are just soaking it up. I know that WDW vets have remarked that main street seems narrow and the castle small, but the castle has always seemed just right to me. And Main Street is narrower than at WDW, which was built to accommodate larger crowds.
DL is an urban park, WDW was built hoping that guests wouldn't go anywhere else while staying there. And one of the things I love most about DL is that despite being smack in the middle of dozens of hotels and busy streets, as soon as you walk into it you feel like you're somewhere else entirely. It doesn't need the distance and acres of land around it to feel secluded, and to me that's magical.
DCA is slowing coming into it's own too. I was there shortly after it opened, and wasn't all that impressed. It was good, but not the same caliber as DL. Slowly it's started becoming more of a destination on it's own, and I'm not entirely sure why. Yes they've added one or two new rides, but I think it's that it's starting to feel comfortable with itself. Everything seems a little more settled now than it did. And I love walking through there and noticing the kitschy things, like "Award Weiners", "Shmoozies", and "Taste Pilot (where great food IS rocket science!)". I'm sorry that the Soap Opera Bistro didn't survive, I think that's something they should have waited to open until the park had come into its own a little more. Perhaps they can open something similar where the waitstaff are celebrity impersonators - that would have a Hollywood feel to it. Or an Improv diner.