I will admit to not reading each and every post here, just skimmed through. But I truly think that everyone's experience is going to be different. I for example, just returned from a 6 night stay (March 4- 10th) and toward the end of that 6 nights the parks really got busy, I guess maybe the start of spring break but I had absolutely no issues with Fast Pass + or wait times being longer than normal. I went to Animal Kingdom at about 9:30 (park opening was 8:00 that day) and had a 10 minute wait for Kilamanjaro Safari and waits for everything else seemed low to normal (5 minutes for Tough To Be a Bug, 30 minutes for Everest, etc.)
With that being said, I loved Fast Pass + and had the opposite feeling than the OP. I for once did not feel rushed, knowing that I had all of my favorites pre-scheduled. No running back and forth from rides to get fastpasses, no trying to keep track of when I could pull my next one, no worrying about them being gone for the day or having the return times not work with my plans at all.
We are normally rope droppers and on one of the days we did that at Magic Kingdom we walked on Space Mountain, Buzz Lightyear then crossed the park and rode Pirates with a 5 minute wait and Haunted Mansion with a 10 minute wait. That afternoon we had the Fantasmic Dining Package at Hollywood Studios so we used our FP+ there and rode Toy Story Mania after dinner at 6 ish and then did Tower of Terror after Fantasmic. We had fp+ for Muppets but didn't need it, there was a 5 minute wait, so changed it to The Great Movie Ride but didn't need it there either it was a 5 minute wait.
We did sleep in 1 day and it was so nice to not have that feeling that we were missing out on prime touring time because we had our plans pre-scheduled. I was also able to change times for things within minutes of our window coming up. I had no feeling of being rushed, in fact for once I felt like I was in control rather than being at the mercy of the old fast pass. I like choosing my time rather than being told what time to come back, which half of the time never worked out with our existing plans anyway. This trip was the first time I've ever gotten to ride Toy Story Mania and we got to ride Peter Pan's Flight twice during our stay. I'm a big fan so I hope they don't take it away because of all of the negativity.