Today I went with my son to put that straight.
Yes there was chocolate, but not too much and the smell wasn't overwhelming either.
Upstairs there were relics connected with chocolate's dim and distant history, that wasn't a big draw for me to be honest. I preferred the machines and the top floor.
Some historic stuff ...
Some less far back historic stuff ...
The view from the museum "deck", which you can get to without entering the museum.
Here's a short video, from our trip today: the machine floor of the chocolate museum.