We experienced the fast-moving FP+ lines on our last trip. We're going back on 4/26, and I'm very curious to see if/how the lines have changed. What I am certain of is that NONE of the lines we saw were like the one in the video!
Honestly, I'm very interested to know if ALL of those people in-line are actually within their FP+ window or not. On our last visit, we encountered a lot of people standing in the FP+ line, only to find out that they were only waiting for their FP+ window to open. I think this causes an unintentional back-up outside of the FP+ line, because the people who are within their FP+ window (and should be able to walk right into the FP+ line) are now waiting for the people who are early to get out of the way. This would be alleviated if everyone would wait until their FP+ return window opens up BEFORE getting in line... but I don't think that's what's happening, based on my experiences a couple of weeks ago. We'll see...
Am I making sense here? LOL I haven't had coffee yet!