I know DL has alot more passholders than WDW does (saw stats somewhere once) but as I live in DL territory its hard to say who gets the more "locals"
I think alot of it depends on locations- For people like me in the west (Utah)- DL is the more affordable option- Its driveable (for me its 10 hours) You can go more often and so you dont need to spend as long (usually 2-3 days) wheras for me WDW is a 5 hour plane flight, you have to stay longer (usually 7-10 days) and its more of a huge vacation (I can do DL for under 300 comparision to a 200 plane ticket and everything else- usually about 1,000)
Wheas someone in Georgia would have the exact opposite for their response- Drive to WDW vs fly to DL-
I do think WDW gets more international visitors as it is a bigger vacation destination but Ive noticed alot doing DL with alot of other things like Vegas and the National Parks in Utah etc-
-em