Just got back from a weekend of a more exhaustive test of the new system (3rd time for me). A few notes regarding FP+:
First..and even tho its common sense, but no one has yet to confirm it that I've seen: Your magic band is linked to you. You can have more than ONE linked to you at a time (at least as of this past weekend). All of mine from previous trips worked just as well as my new one did. So hey..you can collect all the colors if you so choose (not a selling point..dont read it as such..lol). Keep in mind there IS a battery in there, so eventually they will not function
And yes, you can wear one on each wrist
Second...I was able to move my FP+ selections around up until about an hour before they were up. Only issue was the Android app being exceptionally slow, as it has been for months.
Third...I people watched at the Hotel and saw a significantly fewer amount of people with technical difficulties with the new system. My last trip, which was only a month ago, there were many whos bands were linking properly, for one reason or another..this time I counted a total of two.
Fourth...It was said somewhere on here (maybe another thread) that if a fastpass line was empty, that CMs are to run empty vehicles to sort of "justify" the value of fastpass. Well...no. I did POTC twice yesterday at different times, the first one the standby listed was 20 minutes (timed it was actually 23..i was shocked at how accurate it was for once), the FP line had a steady stream of people going in as well. Later in the day, the standby time listed was 15 minutes (it was actually a walk on), the FP lane was empty, so instead of making standby people wait, they were splitting them towards the FP load in as well. So no empty boats were leaving for no reason. I observed several times over the course of the weekend that they were not "holding" standby people back at any point "just because". If there were no FP people, then standby just kept rolling through.
Fifth...myself and the group I was with all agree that if you want to speed up (and make it less annoying) the scanning of the bands, a different style of reader would be best. Instead of it being at a 90 degree angle, having it tilted so the scanner is aimed slightly downwards would make it more "fluent" as well as prevent anyone from having to contort in a weird way. That seemed to be a very common complaint I saw, and I agree with it.
Sixth...Not directly a FP+ issue, but the new credit card readers (with the new system)...are horrible at reading physical cards. Several swipes were required not only for credit cards, but for disney issued gift cards (Doing food and wine yielded SEVERAL testing opportunities of swiping). This just makes things take longer. From what I saw tho, the scanning of your magic band worked every time...take that as you wish.
and finally...Standby times were not far worse than the past. It was a bit crowded on Saturday, so there were lines...but where as many would automatically attribute this to the new system, I can say in my opinion it was more of a case of there just being a lot of people. The actual amusing side thing I noticed was that there were actually lines for fast pass (has been mentioned here before), but the four times I watched this happen (twice was at buzz), the line quickly went away. PAPER fast pass distribution times were actually better than usual (most of the return times were an hour or two later), which I thought was a bit interesting (and the fact that people were willing to get on a standby line for splash mountain of 45 minutes when the FP return was 60 minutes later is beyond my understanding).
From what I saw, there was little confusion on how the system works from anyone I saw using it. It was explained very thoroughly at check in, and most people (ie: the regular people who aren't forum reading in-the-know dis-nuts) saw it as a nice perk..which is how I assume Disney wants it.