Following up from what Brooklyn and DLR29 posted, the FL rides at DL are bunched much more closely together than at MK. Thus a person with an early start can get off one ride and be in line for the next one in 15-30 seconds. Hence an early start focused on FL can be very productive and allow you to do most all of FL in a little over an hour. BUT,
you need to do the FL rides in the correct order on busier days.
Here is a good strategy:
1. Peter Pan first - always first
2. Dumbo
3. Matterhorn/Alice in Wonderland (either order)
4. Tea Cups/Mr. Toad (either order)
5. Pinocchio/Snow White/Carrousel (any order)
All of the above are open during MM and if get to the gates 20-30 minutes early and you hustle you can hit them all in that one hour even on the busiest of days. If you are doing FL on a non-MM day then CJRR will also be open and fits in to the number 5 line above.
Storybook Land Canal Boats is not to be missed IMO and it usually opens one hour after the park opens.