One day last year, DH and I "rope-dropped" at AK, went to HS (had 3 fp's booked), saw the new Star Wars fireworks (awesome!!!) and then rushed to EPCOT (via the walking path to the Boardwalk) to catch Illuminations! We only had 3 day hoppers for our 9 day trip. We did MK all one day, another day we did EPCOT and then MK (3 FPs booked).
Normally we don't have hoppers and we stay all day in a park. HS would probably be our half-day park, morning or afternoon (I've had enough of Fantasmic!), but the Star Wars fireworks are now a must see, so I agree that I'd do the later half of the day.