Universal's system would never work. Have you seen the crowd level difference? While I can't begin to tell you the level of my dislike of Universal after our first and what will be my last visit- their fotl system is great.... I think.
We only used it a couple of times because the park was so empty- not light crowds- EMPTY- that it just wasn't needed. Most times we walked thru either line without being checked. Who cared, no one was there. This was all while Disney was packed with people.
Which btw, leads me to conclude Disney's problem is that they're just too good!
I hope they continue to refine the system and add more features too. Testing is part of that. While not happy to be inconvenience, I also understand the need for real world testing and announcing would stop that from happening.