Very nice cat, a light and one with a not big lateral surface (windage). They don't give sail area but I bet that it is a fast one.
This is a class A boat and compared with a Lagoon 400, it will be a much faster boat...but it would have more stability regarding offshore use?
Well, I would much prefer a Rapier 400 than a Lagoon 400 but regarding that question I would say that the Lagoon has a lot more stability.
Sure, it has a bigger windage but it will not be enough, not by far, for compensate the Rapier lesser beam and much lesser weight.
The Lagoon has 7.25m of beam and 10348kg as displacement. The Rappier 400 has 6.7m of beam and displaces 5000kg.
They have two versions, one open, with just a fixed big Dodger, a bit kind of an Amel type and one enclosed. I like more the Open one, with less weight up and with a better visibility to the helmsman but in what regards functionality and living aboard the closed one is obviously better but than that wheel position does not make much sense anymore.
A very interesting boat nonetheless and one that should be fun sailing.