I was there in September when they were first trying this out at Epcot. It went so smoothly, I couldn't understand why it wasn't happening at HS. I'm disappointed to hear the AK show is gone, but really the "shows" at HS and EP were just shams to try to placate the guests as they chomped at the bit.
Knowing they are opening the turnstiles earlier than 9 is a bonus, but not a big deal for me as I am frequently first at a turnstile. It was the crowd that would bash past you at the rope that was the issue. Even being first at the turnstiles, there was no hope for me to keep up with the guy 2 feet taller than me who shoulder-slammed me to the side once the crowd was given the go-ahead to move forward.
Mob-wise, whether they open turnstiles at 8:30 or 9, the process of inserting the card, placing the finger, waiting for the machine to respond, getting stuck behind people who have no clue what to do, etc. will naturally slow the crowd to a trickle, instead of the giant, trampling mass of elbows all released at once. Sure it's no fun to show up at 8:50 to find out the turnstiles are already open, but realistically, all those people were going to be in front of you anyway (they got there sooner). They are just spread out in front of you instead of piled up in front of you (unless you were planning on elbowing your way up to the rope in front of all the people that had been waiting ahead of you - that's really the only reason I can see someone wouldn't like the new system).