Though we doint use it yet at gerrit.wikimedia.org in the next update we do which is 2.14, polygerrit will be exposed so we can use both gwt and polygerrit through a config.
But theres one problem with that, it doesn't support prefixed urls like /r/ (gerrit.wikimedia.org/r/)
That bug is tracked at https://bugs.chromium.org/p/gerrit/issues/detail?id=5400
But i did find some success with doing the following rewrite rules
RewriteEngine On AllowEncodedSlashes On RewriteRule ^/q/(.*)$ http://gerrit.new/r/q/$1 RewriteRule ^/styles/(.*)$ http://gerrit.new/r/styles/$1 RewriteRule ^/bower_components/(.*)$ http://gerrit.new/r/bower_components/$1 RewriteRule ^/elements/(.*)$ http://gerrit.new/r/elements/$1 RewriteRule ^/config/(.*)$ http://gerrit.new/r/config/$1 RewriteRule ^/accounts/(.*)$ http://gerrit.new/r/accounts/$1 RewriteRule ^/login/(.*)$ http://gerrit.new/r/login/$1 RewriteRule ^/changes/(.*)$ http://gerrit.new/r/changes/$1 RewriteRule ^/projects/(.*)$ http://gerrit.new/r/projects/$1 RewriteRule ^/c/(.*)$ http://gerrit.new/r/c/$1
But that doesn't actually fix it but rather lets users test the new skin out in limited compacity.