Allow to re-enter password immediately after failed attempt
I'm not sure if this was something you were able to do with the previous lock screen, but at least on Windows, if you fail to enter the user password correctly, it lets you enter in again immediately. I believe the gnome lock screen should allow the same, instead of having a 2 second wait before the text box becomes ready again.
What will typically happen is that I enter my password incorrectly, upon seeing it fails, I enter it again immediately, but then it missed out on the first half of the password because of the text box timeout. I believe getting rid of this timeout will give a better user experience in that it will make the system feel more responsive.