Actually, if you want to copy most/all settings for all gnome-based apps (like gedit, launchers, etc., Unity included) from one account to another, you can use
dconf dump / > mysettings.ini and on the target account:
dconf load / < mysettings.ini.
In addition, you could manually review all the setting in
mysettings.ini and adapt them as needed (you'll find there the
icon-size and everything else related to Unity).
If you can't identify a particular setting by looking through the dump, you could find it by first doing a dump, then changing the setting via the standard UI, then comparing the original dump with a new one, like this:
dconf dump / > ~/tmp.dump
change a setting via the UI
diff -B5 <(dconf dump /) ~/tmp.dump
-B5 is to additionally get 5 lines before the match, for more context -OR- use
dconf watch /)
The settings that are dumped with
dconf dump / are the values that differ from the defaults, i.e. you won't see there settings that currently have their default values. For a complete list of all available settings with rather complete explanations, possible ranges and default values check the files in
/usr/share/glib-2.0/schemas/. You'll see there
10_xxx.override files, this is the preferred way to override the settings globally.
As to the comment by @mauek-unak, compiz settings (like the
icon-size) were not working under a VM because the default compiz profile under low graphics is
unity-lowgfx, but the setting modified by
gsettings set org.compiz.unityshell:/org/compiz/profiles/unity/plugins/unityshell/ icon-size 64 is for the
unity profile. The strange thing is that even with
dconf dump/load the setting of the current profile
gsettings get org.compiz current-profile is not having effect on the actual compiz profile.
When lowgfx is in play,
~/.config/compiz-1/compizconfig/config will have some settings and you should change it with something like:
sed -i '/profile = / s/-lowgfx//g' ~/.config/compiz-1/compizconfig/config
The change is applied immediately.