I read all the time, post infrequently so thought I'd share my observations...
Cons:
1. I was not a magic band participant but heard a lot of complaints about fastpass+ mainly due to issues at check-in such as ADRs not linked to the band although the user linked it online to their account, tickets not attached to the band, etc. which took several diff vacationers HOURS to resolve during check-in.
2. I had old paper tickets I bought a couple of years ago (non-expiration, I go to the parks a few days per year) and they kept telling me I had to switch over to the new media. I didn't want to because I didn't want to lose my +more option and figured it's still in test mode anyway, they said it wouldn't, but with all the headaches others were having I wanted to avoid it. I had no issues on the first 2 park days (MK and HS) but on my 3rd park visit (and final for this trip), at Epcot, the woman said this had to be the last day I used my tickets because I needed to switch. I said OK and went on my way, then when I tried to use my tickets for fast passes for Soarin', they were deactivated and the machine wouldn't give my fps!
I complained to a cm nearby who asked if I used those tickets to get in that day, I said of course. They gave me a fast pass card (labeled not valid for park entry) for each ticket Iso that I could get fps for the day so crisis averted but I thought that was messed up of her to deactivate and not even tell me other than "go to guest services for your new tickets".
Pros:
1. Super low crowds. At MK every single ride was a walk-on, we didn't wait more than 10 minutes for anything. At Epcot only Soarin' and Test Track had waits (50-80min), everything else was 10 minutes or less. At HS, other than TSM everything was a walk-on, we did wait about 25 minutes for RnR but that was the longest and only real wait.
2. I was worried about the food quality reading on the other forums on here but everything we had was really fresh and tasty, CM was meh but still edible.
3. All the characters, except for Mickey at CM, were great and took their time with the kids. Alice @ Epcot was very funny with all the kids and Sorcerer Mickey @ HS was great too, he made a really big deal of my DS4 giving him some Mickey stickers which really made my son's day.
If anyone has any specific questions, I'd be happy to answer.
Cons:
1. I was not a magic band participant but heard a lot of complaints about fastpass+ mainly due to issues at check-in such as ADRs not linked to the band although the user linked it online to their account, tickets not attached to the band, etc. which took several diff vacationers HOURS to resolve during check-in.
2. I had old paper tickets I bought a couple of years ago (non-expiration, I go to the parks a few days per year) and they kept telling me I had to switch over to the new media. I didn't want to because I didn't want to lose my +more option and figured it's still in test mode anyway, they said it wouldn't, but with all the headaches others were having I wanted to avoid it. I had no issues on the first 2 park days (MK and HS) but on my 3rd park visit (and final for this trip), at Epcot, the woman said this had to be the last day I used my tickets because I needed to switch. I said OK and went on my way, then when I tried to use my tickets for fast passes for Soarin', they were deactivated and the machine wouldn't give my fps!

Pros:
1. Super low crowds. At MK every single ride was a walk-on, we didn't wait more than 10 minutes for anything. At Epcot only Soarin' and Test Track had waits (50-80min), everything else was 10 minutes or less. At HS, other than TSM everything was a walk-on, we did wait about 25 minutes for RnR but that was the longest and only real wait.
2. I was worried about the food quality reading on the other forums on here but everything we had was really fresh and tasty, CM was meh but still edible.
3. All the characters, except for Mickey at CM, were great and took their time with the kids. Alice @ Epcot was very funny with all the kids and Sorcerer Mickey @ HS was great too, he made a really big deal of my DS4 giving him some Mickey stickers which really made my son's day.
If anyone has any specific questions, I'd be happy to answer.