Yes, and no.

You'll see the titlebars anyway because they contain worthwhile controls now. You know, like with Chrome putting the close buttons on the tab bar. Evince (a document viewer) has the page number, back-next, find, annotate button, zoom controls, options dropdown and a lil' more on there, for example.

The other thing is that the control buttons you won't want are opt-out:

https://wiki.archlinux.org/index.php/GTK%2B#Client-side_deco...