I want to say I like Casey's Corner better. I like there Hot Dogs and plus I love the hot cheese sauce. I also like the corn dog nuggets. Probably the only minus between that and Coke Corner. Is, that I don't like sitting on the bleacher while trying to watch for my friend Peg Leg Pete to be on. The bleacher makes it hard to eat. I like the seating at Coke Corner is much better. But I will still pick Casey Corner over Coke Corner. Because I like Casey's Corner food more.
(I'm only judging from the insides. When I'm talking about the seatings.)
I quite enjoyed Casey's Corner at Disneyland Paris... nice hot dogs and there are a lot of seating options... inside, outside or in the covered walkway behind main street. I've never been to WDW so I wouldn't know but I assume Casey's Corner there is pretty similar (except for the seating in the walkway).