Depends on a few things: Do you and the people in your party enjoy being on a schedule? Is your main goal going on rides?
We used it on during our Oct. 05 trip. I printed out a few schedules and took them with me. My husband and children were fine with it. MIL and FIL did not seem to understand what we were doing, and why. They kept wanting to stop to see things, take breaks ( after an hour or so in the park), etc, etc. We tried to explain to them that we were focusing on rides for one day, and we would do the rest (stop and look, watch shows, shop, etc) after the rides and on the other days. My lunch time we gave up. Had it just been our little family of 4 it would have been great.
The program is easy to use and understand. The price is reasonable compared to how much a trip to Disney costs!
I wouldnt use it every day of your trip. I would maybe use it for one day, then take things as they come the rest of the trip. It is a great tool for getting the most rides in a day, but when you rush from ride to ride you miss the magic the park has to offer. The chance meeting of a favorite character. A musical act. "Push" the garbage can in Tomorrowland. The sounds and sites on main street.
If nothing else, get it and run some days through it. Vary the rides and lands, and what it comes back with. You'll be able to find out things like, Dumbo has a 15 min wait rigth after opening, but an hour later its at an hour and never gets better! You learn to go to "-----" ride first thing in the morning, because everyone else goes to "-----".
They will stand behind the product. I posts my experience in a trip report. They read it and PM'd me, and offered me a refund. I didnt take it. It wasnt their fault my inlaws are elderly and couldnt follow a plan! LOL