I’ve got X2Go working properly on a Mac with OS X 10.7.5, and it should be able to work on newer versions as well. The issue was the native X server provided by 10.7.5, it is garbage.
I loaded XQuartz and not only did the issues with X2Go as far as keyboard translation and display resolve (sound is still borked), but it also fixed another annoying problem and that was marginally functional, sometimes not at all, cut-n-paste.
If you have a Mac OS X 10.7 or earlier (but still OS X) install XQuartz (very easy just download and click on the file, then log out and in again) and you can use X2Go to access all of our servers graphically. It will also fix cut-n-paste issues the native X server has.