Hello.
I have read that Debian comunity has plans to review the default desktop enviroment for future releases, since some people are not very glad with current Gnome 3.
Please let me give you a personal recomendation: take a look at the Cinnamon desktop and take it in consideration.
Cinnamon is already packaged in Debian, it is modern based on Gtk3, confortable and has a good perfomance.
Thanks for your atention.