It's surprising how well these ships sail; although square sails are often thought of as only being effective going down wind, they sail somewhat into the wind fine. And of course, you don't have to worry about a bad gybe removing your rigging.
I was in Norway a few years back and took a tourist trip in a 2/3 replica of a Viking boat found in a burial mound - the crew took us up the lake, turned round and came straight back - it was remarkably nippy and seemed to handle very well. I'd be interested to read how the much larger ship here performed under sail.
For square riggers the problem is rather tacking, because then you're backing the entire sail area and putting strain in the wrong direction for the rigging.
The rigging is built to withstand immense pressure from behind and the side, not from forwards. For larger square riggers they do wearings when the wind starts to pipe up to mitigate this.
From talking with people involved everyone was surprised how incredibly well she sails. But it was a lot of learning to get to that point with the bottom reefing and strange sheeting points affecting the balance.
How weatherly the ship is (how close to the direction of the wind it can sail) seems like such an important performance spec on a sailing ship, but it never seems to be listed.
