our first trip 3 years ago we didn't use fast pass at all,i know it isn't fast plus but we still managed to get on all the rides we wanted to.
The reason we didn't use fp was because by 11 am or so all the fast passes for the day were gone. At DL they never run out of FP,at least I have never seen it.I was quite shocked by it.
also at DL they will honor a FP after its expired time, even from 10 hours ago.
This trip we are using fast pass plus but don't really like having make an appointment for a ride.