I was impressed with the B1 at the St. Barth Catacup. For an old boat I saw quite a bit of it towards the back of the 1/3 of the fleet. Boats with thin hulls but decent volume can do well in that St. Barth chop.
If you have questions on it I would contact Manu Bolougne the builder, he will be sure to answer any questions for you. I know he thinks very highly of the B1, as he should since he won a worlds on it.