I installed Nemo from the Mint packaged for Ubuntu archives. This updated it, made some more nemo-* packages available and fixed the breadcrumbs, but I was left with the useless disk space indicators. Here's how I fixed those:
Create your own GTK+3 theme as follows
First, duplicate the Adwaita theme with the name Adwaita-custom
$ cd /usr/share/themes
$ sudo bash # easier than prepending every line with sudo...
# cp -ar Adwaita Adwaita-custom
# cd Adwaita-custom
# sed -i 's/Adwaita/Adwaita-custom/' index.theme
Now we add special CSS for Nemo
# cd gtk-3.0
# echo '@import url("apps/nemo-custom.css");' >>gtk.css
# mkdir apps
# $EDITOR apps/nemo-custom.css*
Now in that file, here's what I put:
/* For Places Sidebar diskfull indicators */
-NemoPlacesTreeView-disk-full-fg-color: #4a90d9 ;
-NemoPlacesTreeView-disk-full-fg-color: shade(#4a90d9,0.5) ;
Save and exit your editor. You can now drop root privileges, too, and/or exit your terminal shell.
Now select Adwaita-custom as the GTK+ theme in the tweak tool ("Advanced Settings") app.
Here's mine now:
PS. Big thanks to Roman Raguet for the comment which linked to the original nemo css.
PPS. Oh, in my screenshot, you like my small titlebar eh? Yeah, nice. Here's how.