Thank you!! This is awesome.

I wish it had no black space in the bottom

Does a great job of simplifying the Gmail interface, giving me more room for messages. Plus, they fixed the issue with the search bar not showing up when set to auto-hide. Nice!

Make sure your left sidebar isn't minimized before turning on "Make left sidebar autohide," otherwise it doesn't re-appear quite right.

Great idea but make that hover area bigger from top, now it working only from the area where the buttons are, just larger the area over it, to center perhaps.