I think in this sort of size you will find the "down below" a problem when heeled over. No room to keep your feet under your body...no room for the upper body. This is interestingly less of a problem with sitting head-room.
She will be wet in a seaway. Your top-sides and top of the bilge are nearly straight and vertical, when you heel over as waves break slightly on the side, the wind will lift some of the water up over, and into your lap.
What happens when you have no wind and a large left over sea...I'd guess she will roll deeply and tirelessly.
I'd want a little more form stability.
After all the criticism, I am charmed by this design and Atkins Joan, which I have sailed on once briefly. In normal sailing they do not tend to roll and jump as much as some others. In a blow I think Joan was slower than her waterline suggested, on the other hand, she did not as often need to take several tries to get over a wave when working to windward in a sea. I would plan for a sloop or cutter, much as I am a fan of divided rigs for cruising boats. In this small size the mizzen gets in the way. More sails in the working rig means more time invested in getting under way and putting her to bed at the end of the voyage.
How about these from Bill Garden, or the "Spice Island Cutter"( which I could not find a pic of)