Probably like nothing else you’ve ever sailed. Although she’s over 43 feet long she only weighs a bit over three tons. There isn’t a lot of sail, on the face of it, but in wind of force 3-4 she easily gets up to 5-7 knots on a reach, and will go to windward at 6 knots without apparent effort.
Off the wind we carry a big asymmetric spinnaker, originally made for a catamaran, and under spinnaker and mainsail we’ve recorded 10 knots on a broad reach for extended periods (the log won’t read over 10 knots).
The key thing is that she’s very light, and there’s really not a lot of sail, so everything is easy to handle. “It’s a bit like steering a really big dinghy” one of our crew said.
The key thing about sailing Korybant is to have the right amount of sail up, and to keep the boat balanced. There are three reefs in the mainsail, and we carry three head-sails, varying from a #1 genoa with an enormous overlap (mostly for racing), down to a #3 jib with no overlap. Anything beyond force 5 needs a reefed mainsail and a smaller foresail.
There’s a video showing us sailing here, most of it taken from a Dutch boat: https://www.flickr.com/photos/89265154@N00/16167359990/