Has anyone taken this route? I'm concerned about flying this carrier in coach and feeling too cramped.
Can you give us flight numbers and we can look up the flights to let you know.
If you're flying Delta from ORD to JFK, you'll probably bee on a regional jet which can be a little cramped but the flight is less than 2 hours.
From ORD to PRG, you'll be flying some type of widebody jet. More comfortable than a regional, but very little difference regarding space and size than any other airline.
I do feel that Delta service is slight better than other domestics but coach is coach and there is not much room.
I have traveled on Delta from JFK to Prague and found coach to be extremely comfortable. I usually book an aisle seat in the middle set of seats and find that the space is quite adequate. Check out the equipment Delta is using. When I traveled 2 years ago was a 777 I think.