To be honest, the new fast pass+ system won't affect us much.
We are morning people, even on vacation, so we are up and at rope drop every morning. We even have 8am breakfast a couple of mornings so we can be in the parks before they open. We get a lot done early in the day, and either go back to the resort for a break, or take it slow if we stay in the parks.
Actually, fast pass + will be great for us because we won't have to go out of our way to get FPs for Toy Story Mania or Soarin, we can get a decent seat for Fantasmic without any worries, and I'm sure we'll find other ways to make the new system work in our favor.
There were negative with the old system, and there will be negatives about this system. I don't see any negatives getting in our way of having a great time though.