Exhibition was wonderful and package was good value for money compared with standard cost of exhibition.
BUT... The voucher did not specify where and how all documentation was to be collected.
We tried, twice using email, then by phoning the provided London number (accessible only on California time!) to be told that the documentation would definitely not be sent to our home address or the hotel.
We identified the location from the Internet and travelled there (in searing heat) from the airport with all our luggage to the head office (after being redirected) to then be informed that it had, after all, been sent directly to our hotel.
Bearing in mind that we were only in Vienna for three days, immediate access to the 72 hour Vienna pass was rather important.
The passes were indeed waiting for us at the hotel but did not include the advertised books of vouchers.
The voucher for the Belvedere was in the form of an invoice but did not specify entrance to the Klimt exhibition, resulting in confusion at the entrance desk - subsequently resolved by direct involvement of the manager.
In the end we thoroughly enjoyed our visit, but it could have been made considerably smoother by some common sense instructions and basic info on the downloaded voucher.