We have been on three Viking River cruises and one Viking Oceans back in 2015 from Barcelona to Istanbul. So we were Viking fans and had looked forward to this cruise for over a year due to the opportunity to experience the Amazon.
Overall, our experience was negative and I would advise that anyone considering this cruise wait until you hear that Viking has worked out all the kinks.
PROS
Slightly larger than Deluxe Veranda. Very close to front of ship but not noticeably rockier than middle. Includes daily restocked bar (incl beer and spirits)
Did the Santa Lucia Nature walk. So many people made it impossible to encounter any wildlife (too noisy). Really just a long walk on a meandering path through the forest. Guide explains different tree types and shows a few (abandoned?) animal burrows but not much else.