Our cruise (we are Dutch) with the Marco Polo was not too bad taking into account some negative reviews on this site.
The ship is old and that shows. During our trips there was a lot of repairing and painting going on, restricting the available space on the decks.
The itinerary is interesting but remember the Amazon is very wide so the panorama is rather boring and there are many seadays.
Cabin 358, only one pothole and no direct view, situated right in the backNoisy, constantly crew members passing to the closed deck at the back, slamming the door also at night time.Regularly big bangs from the waves agains the hull, difficult to sleep