There were issues with CMs getting injured by ECV users coming through the gates too fast/wildly. I've witnesed ECV users slam through the gate that was not fully closed between transactions, with the gate hitting a CM.
When they first started this ECV line, only ECV users and their family could use it. Now anyone can use it (they haven't been limiting it) and I love getting in line behind the family trying to come in who only have handstamps, then they have to get a lead to explain they need tickets also, so they rummage through backpacks/purses/etc.... while I can't change turnstiles like I could have prior to the new ECV gate. Don't come in with me, it ALWAYS happens when I am in line...