I use PreFlight all the time. The facility is clean and well-lit and it's a pretty convenient walk to the 44st airport SkyTrain Station, although the 44th St/Washington St intersection can be sketchy at times. If you've closed all the rings on your Apple iWatch Activity App and don't feel like walking, they have shuttles to the airport that you track their location thru the PreFlight app. Using the SkyTrain, it takes less than 10 minutes to get from the PreFlight garage to Terminal 4. Daily parking rates get less expensive the higher up in the garage to park. Signing in and out of the garage, payments and making reservations to get even better rates are all done with the app.