I don't pretend to be an expert by a long shot, by the way. I began studying yacht design a little more than a year ago after leaving my motorcycle in Newfoundland before it came to a complete stop. Facing the dark of winter with a shattered shoulder, I needed something to occupy my mind.
The Mariner 19 is closely based on the Rhodes 19 -- it's the same hull with slightly plusher accommodations. Philip Rhodes had a heck of a lot more experience in yacht design than I can ever hope to have. However, he also had a racing bias where the 19 was concerned.
Racers like to have a lot of sails. So far as I can determine, there were at least 4 different sizes of main (at least I have 4, all of which are completely unadorned by reef points), a 155% and 135% Genoa, standard and storm jibs, and various spinnakers. It make's one's head spin!
My boat is a "2+2," or capable in theory of sleeping four people. I suspect that's a subterfuge. We all know that a V-berth is not intended for sleeping, but sail storage. The crew is supposed to wedge themselves in the coffin-like quarter berths. Luckily, in my example, there is a lazerette over the foot of each quarter berth. My size 12 feet would never fit otherwise.