We have had three trips with FP+ fully rolled out. I won't discuss the strategy for our first trip with FP+, as during that trip the legacy system was still operating.
We used the "try to use all FP+ in the morning in order to be able to book a 4th" strategy on our first FP+ only trip in August. It worked well then, but crowds were also as low as I've ever seen them, and the 4th FP+s we pulled were for Star Tours. We were able to pull a 4th FP+ for POTC that trip, for late at night (9;55-10:55 according to
MDE), but I'm not sure if I tried for an earlier slot or not. After that trip, I was relatively satisfied with FP+, but we also didn't really need it much because crowds were so low.
After that trip, though, I began to loathe FP+. Instead of derailing this thread with commentary for why I dislike it, I'll just give facts. Luckily, MDE's "Show Past Items" feature gives me the data I'd like to share. I'm just offering facts for what we experienced...you make the call whether this would be satisfactory for you. I will say that we are not local, are a party of 4, and we have young kids who like to re-ride their favorite rides and generally avoid anything that falls into the thrill ride category. BTMRR and Splash are favorites; Space, EE, and RNRC are avoided. We generally arrive at RD unless we're having a sleep in day, which we do the mornings after parties and late nights.
Looking in MDE, we had the following experience:
December 14th: At MK; last FP+ window was 1:40-2:40. Was able to snag a POTC FP+ for the group by taking two overlapping times (4:40-5:40 and 5:10-6:10).
December 15th: At DHS (this was a late arrival day due to going to
MVMCP the night before); last FP+ window was 2:20-2:35; was able to get a 4th FP+ for Star Tours for 5:50-6:50.
December 16th: At AK; last FP+ window was 2:05-3:05. No 4th FP+ available.
December 17th: At DHS; last FP+ window was 11:35-12:35. No 4th FP+s available for Star Tours, which made us sad pandas. So we hopped to MK and managed to pull overlapping FP+ times for the four of us to meet Mickey with windows of 2:30-3:30 and 3:30-4:30.
December 18th: At Epcot; last FP+ window was 11:15-12:15. No FP+s available for anything we wanted for the rest of the day at that time.
December 19th: At MK; last FP+ window was 11:50-12:50; 4th FP+ pulled was for Aladdin at 1:10-2:10, but when we got there, SB wait was only 10 minutes. Tried to change it to something else, but there was nothing available that we wanted to ride for the rest of the day.
December 20th: Departure day; so we were only able to be in the park until noon. POTC was down during our FP+ window and we didn't want to ride any of the replacement experiences, so we left the park after using only two of our FP+s.
On our trip last month, we were only at Disney for 2 1/2 park days, and were going primarily for SWW, so we didn't try for a 4th any of our days.
What I found frustrating about trying to use the FP+s early is that with the exception of the super popular rides (Peter Pan, 7DMT, and TSM), there is really no reason to use a FP+ before 11:00. So it almost feels like you're wasting a FP+ just to try for a 4th...and even by noon or 1:00, the rides that still have FP+ availability are either really far out in the future or are things with short SB rides later in the day. So for us, that strategy didn't really work well because then we had no rides that we really enjoyed doing in the afternoons. I think I'm going to change strategy on our next trip and see if it works better, and other than the super headliners, book most of my FP+s for mid-to-late afternoon or early evening and not even bother with the 4th. For all the stress it caused, the 4th just doesn't seem worth it to me.