I did something to configure it so that now all of my labels have collapsed in and become miniature icons. I have to wave the mouse over the icons to have it expand back out to labels. Basically the entire thing feels to me like a design for Android or IOS phones, and they are trying to shovel that at desktop users too. While I am sure the ultra-efficient use of space is something I will get used it, I rather liked the current Gmail because things were just laid out in a way that made use of the extra desktop space of a real computer. Overall I feel like I am fighting a phone app and trying to find ways to reconfigure it as a desktop app.
Also, that use of larger fonts is seriously annoying me. I liked being able to see more pieces of email on the screen in the classic version.