We got back on May 3rd. This was our third or fourth trip with FP+. For us, FP+ was a downgrade from legacy FP. Is it better than standing in standby lines only? Sure. However, not a lot better because we only had 3 rides where we were standing in standby lines. Sure, you can probably get a fourth FP, but they were always for rides that didn't need a fast pass in the first place. I don't see a point in getting a fast pass for Imagination when the wait is <5 minutes or Spaceship Earth when it is <10 minutes. We ended up getting fewer rides done and spending more time at the resort.
We are rope drop people by nature. We didn't set our alarms for the majority of the trip but we still woke up, were able to get ready at leisure, have breakfast, and be at the parks for rope drop each day. We just don't "sleep in" (we do, but our idea of sleeping in just isn't as late as most people's). We found the fist 2 hours at the parks to be very important, especially at Magic Kingdom. With most people heading to Fantasyland first, we would be able to get done so much in Frontierland, Adventureland, and Liberty Square with little-to-no wait before lunch. We would use our fast passes around lunch time. Usually, we had one before lunch, ate, and then used our two. By that time, lines were long and fast passes for rides that might actually need fast passes (the mountains, Peter Pan's Flight, 7DMT, etc.) didn't have passes available. We would usually go back to the resort and go swimming or go resort hopping.
One situation where the negatives of FP+ really stood out to us was on one of our DHS days. We had a FP+ for Tower of Terror at 11:00 and Hollywood and Vine reservations for noon. We made sure we were in line for Tower of Terror right at 11 and the line was very very long... and not really moving. Various people were walking up to the workers and coming back reporting that it was going to be 45 minutes, that the ride was down, that it had gone down earlier, and other different stories. Since we weren't really sure what happened, I went up to ask. The cast member told me that they were only able to run one of the elevators so the lines were moving very slowly. FP+ was expected to be about a 45 minute wait and standby was 2 hours. Since we didn't want to risk missing our dining reservation, we decided we needed to get out of line and do something else. We didn't want to wait 45 minutes only to figure out it was going to be longer, you know? Unfortunately, we were unable to switch our TOT fast pass for a better time that worked with our schedule. With legacy, this wouldn't have been as much of a problem because you weren't scheduling so much of you day and you could have overlapping fast passes. So that was one that really stood out to us as a pain.
We also hated having to go look for a kiosk if we decided we wanted to ride a ride with a FP+. I get amused at the people who say that they like FP+ because they no longer have to run across the park for the sole purpose of obtaining a FP and then head back across the park to join their party (something we never did anyway) or have a FP runner anymore (again, something we never did) because we ended up having to go searching for a fast pass kiosk to see if we could even get a fourth or fifth fast pass. At least before, you could look on your phone to see when the fast pass return times were and if any where still available. Now you have to go to a kiosk to find out. Hope there is a kiosk nearby when you decide you want to go get yourself a fourth or fifth fast pass. And I hope that they have something available that you will want. It seemed to us, though, that the only times a FP+ was available was when you didn't really need it, anyway. You weren't going to be able to get one for something you would actually need a FP+ for.
So I don't really care for FP+. It did not improve our trip at all, unless you count the fact that we spent less time in the parks which means less time shopping and buying snacks but, as a shareholder, I'm not a fan of the idea that people are spending less time and money in the parks. I have read that Disney execs were saying that FP+ was designed to keep people in the parks. I fail to see how.