The value of Ambassador is in the free weekend night certificate and the 4pm guaranteed late check-out (for me).

If you will use the 4pm check-out then that has value, as does the upgrade and the 5000 points for signing up. Not sure you get to $200 unless it is a long stay and the upgrade makes it worth it - unless you are there over a weekend and you cancel 2 of the reward nights to replace them with buy one, get one free using the voucher.