I feel that FP+ allows us to have way more spontaneity than we ever have before! Mainly it is due to knowing we have our top choices locked in. The last 3 trips we have had FP+ and these 3 trips have been the most relaxing ones ever because there was no worry of "OMG, are we going to be able to get on Peter Pan or TSMM or Soarin?!" Being scheduled in advance gave us a HUGE sense of relief so we could spend time doing other things.
We always made our FP+ selections for our second park of the day, that way when we arrived we just waltzed onto our rides - it was awesome! It felt so carefree and easy.
I LOVE not having to run all over to retrieve paper FP, only to find out once you get there they are gone or the time is much later than you wanted. At least at a Kiosk you can check what's available and at times, manipulate the arrival time to suit your needs. Our last trip was 6 days (May 22-27) and only once did I encounter lines for FP+ kiosk and that was at MK. Took about 10 minutes. The lines look overwhelming, but they really do move pretty quickly as there are several kiosks, plus CMs with handheld tablets.
Anyway, sorry that so many others don't like it. But for my family, it works great!