This.
As a local, I play around with the app a lot and very rarely find it hard to get FP+ or does the system make it hard for me to "wing it". We're actually going to DL in a month and my mom, who generally just finds things out as they happen or when I mention, was weirdly upset that we'll have to run around to get our FPs. For us, FP+ actually helps us relax more than we used to in the parks as all we need to do is click on the app and all the info or whatever we want to do (whether it be book a FP, check wait times or get a restaurant reservation) is at our fingers. WDW by far has the best app - much better than Disneyland's, Uni's or Seaworld's.