We did CMV once 6 years ago, it was the only ship going from Cape Town to UK when we wanted to come home in April.
This was year after we'd done same journey on Aurora. CMV not in same league as Aurora, very basic , cheap and cheerful. Enjoyed the cruise but that was because of the fellow passengers not the ship.
Ambassador cruise reviews are very mixed, some, about half the people think they are fine and good value, the other half think they are very basic, poor foodand don't live up to promise