Many of the French boats have polars as part of their marketing
material. They are VPP generated, and not actual sailing experience. They are very generous - I know of none that have actually met those polars.
They would be meaningless in deciding between makes/models. Most boats come with poor sails
and do not meet design weights right out of the box. Even accurate polars would not tell anything about how any one boat will handle cruising gear
or planned sailing conditions.
On the other hand, they are very easy to generate once you have bought a boat! There are even software
programs that automatically collect the data while you are sailing and give you a nice averaged graphical data set.