We stayed on the Lotus in January and it was the perfect place for 16 people. It was really warm and cosy and the living room area was big enough to spend the evenings there. The beer tap that Olaf provided made it even better (We can totally recommend to book the beer keg!).
The beds look tiny on the pictures but are actually quite comfortable, even for taller persons. There are two showers, two toilets and a sink in every room - so no problems in the morning with everyone getting ready. Towels are provided.
We were located at Sumatrakade, which was only six stops from Amsterdam Centraal by bus and there also was a tram nearby that took us to all places further south - perfect!
Olaf and Nicci live on the other half of the boat, so they're close if any help is needed. But they still let you have your little party on the boat as long as you keep the outside noise down so you don't disturb the neighbours.
We all had a great time and it was an unique experience - thank you!