Went today. We're Florida resident AP holders. We'd usually use one or two FPs per day, depending on the crowds, so we enjoyed having three set FPs and not having to run around the park to pick up paper FPs and returning later in the day.
I liked it, to be honest. Got FPs for Space Mountain, Pirates, and Big Thunder. The only negatives in my opinion were a long line at the kiosk, and when we returned to Space Mountain the ride was down. We were able to go back at any time and use the FP+ line once the ride came back on (or use FP on another ride). Because of that, the FP line was longer than usual, but substantially less than the 110 minute standby line.
Feedback: I would like for Disney to allow AP holders to book FPs on the app, and increase the number of FPs to five.