I've done both and as long as you get there 30-45 minutes ahead of park opening you do fine. The thing I like about EMH, is that only half the park is open. Especially MK. You can get the headliners done on one side of the park and wait at the rope for the other side to open at 9:00 and then get to those headliners.
If you wait for regular entry, you either have to quickly ride the couple on one side of the park and head straight over to the other, or use FP, which is OK too, I guess. I just think that if you're early risers anyway, it's more relaxing using EMH. I think the key either way, is that you get toward the front of the entry line, so I usually figure the wait at the beginning of the day is "hopefully" my "big" wait for the day.