I have been to both (mostly to WDW but more recently have taken a trip to DL) and enjoy both for different reasons. I have a trip coming up in May, and I'm waffling back and forth between the two. There are good reasons for both, but I was wondering what other criteria that I am missing.
Here is what I have so far on my chart:
Weather
Price of flights
Price of hotel stay
Price of park tickets
The parks themselves (like, EPCOT vs DCA)
The different rides (love Indy! love Rock'n Roller Coaster!)
Restuarants
Other Activities in the area that aren't Disney
Dole Whip (ok, it's at both, but I decided to put it on the list)
What else?
As far as your criteria go:
- weather: we greatly prefer the weather in Florida to California. I dislike the California smog, it's never warm enough for us,...
- price of hotel stay: I'd guess if you stay on site at either place, you'll find lower prices at WDW than DL (since there are many times more on-site hotels). Obviously, there are a lot of 'good neighbor' hotels very close to DL. I can't say we're fans of Anaheim, or many of the good neighbor hotels; I hate the kitschy feel of the area just outside the DL parks;
- parks themselves: we haven't been to DCA since Cars Land opened, but I really, REALLY dislike the paradise pier area. Future world isn't my favorite, but we LOVE world showcase. We're also big fans of Animal Kingdom. Lots of construction going on at WDW, though;
- rides: The teacups and IASW are more aesthetically pleasing at DL than MK. POTC is better, and longer, at DL, than at MK (but we still enjoy the MK version). We prefer the MK Haunted Mansion. Tower of Terror is my hands down favorite ride ever, and the Hollywood Studios version (with the elevator car that actually moved vertically, and has randomized drops) is vastly superior than the DCA version. Indy is better than Dinosaur, but both are fun. Rockin Roller Coaster is worlds better than California Screamin. We usually avoid the Matterhorn Bobsleds since we value our backs and the ability to move around after riding;
- restaurants: Idk the exact numbers, but I think there are something around 75 places to get food at DLR (including everything from churro carts to sit-down restaurants), and over 240 at WDW. I've heard people say the food at DLR is better than at WDW; but I've also read that more so applied to quick service places than sit-down restaurants, and isn't really the case anymore, anyway;
- area activities: If you have a car, you could make the drive to the San Diego Zoo or other California attractions. Of course, that takes up quite a bit of time; and obviously LA traffic is a nightmare. (We once did a San Diego-Vegas-LA trip, but took about 3 weeks to do it.) Universal Studios Hollywood doesn't yet have a Harry Potter land (and when it does, it will probably be smaller than at USO), so that might be a consideration;
- grad nights: Grad 'Nights' at DLR are scheduled for several days in May. I've heard the crowds and mostly unsupervised teens don't necessarily break a trip, but it's probably best to avoid these days if possible;
- flower & garden: The F&G Festival at EPCOT will be going on through the beginning half of May;
- Star Wars Weekends: Star Wars Weekends at Hollywood Studios are also scheduled for various dates in May. This could be a positive if you're a SW fan, or a negative if you want to avoid the crowds.