I too have used the virtual, various GSIs and currently use the madsen at
one office. the gsi-16 is by far my favorite to use, unless you need /can
afford the gsi-10, and can now be linked to a pc for remote transfer of
information. the virtual, in my humble opinion, is a horrible machine that
is clumsy to use and configure quickly, particularly for tests such as VRA
and BOA where you want to switch speakers without fuss.