Totally agree with this post. We are testers and although I was initially freaked out and wanted to "opt out" if possible, I'm now looking forward to trying it out. I would be less enthusiastic if we were going during a crowd level 9 week vs. crowd level 4 or 5 though.
I found out about the test last Tues am at 5:45 am and went in and spent about 2 hours making and editing my FP+ choices. As others have reported all headliners are available, but I found that for us Wishes and MSEP were never an option and Fantasmic! only showed up for one day and was for the second showing. So there may have been some "tiered" options for us because we have discounted convention tix, I'm not sure.
Several times last week I went in to change my selections after rethinking my strategy and the headliners were still available but at less desirable times. Now at less than a week from starting I'm at the point where I can't really do any more editing because of availability. Example: I booked FP+ for my party of 4 for 12:05 for BTMRR and after watching a youtube video my younger son has said he will not ride it. When I try to edit the FP+ for just DH and him for a different ride I get "we're sorry, there are no other rides available during this time." Less than a week from when booking started and I can't even get so much as a Philharmagic FP? Really? I could get something if I changed the time to 2 pm but we'll be long gone by then.
The interface for choosing FP+ is clunky. I will often have to log in and enter my password 3X during an attempt to change a FP+ attraction or time. I will also get a stuck screen where it is "loading" and never gets there. I won't want to be fiddling with that on my phone while in the park for sure.
So far my perception is that if we are able to go during a less busy time there's a chance the good may outweigh the bad. If I were going during a busy week I would really be questioning whether the resort and
ticket prices were still worth it.