I’ve never tried Quince before but I think I may have seen some marmalade made with it at the Asian markets.
This quince I showed a picture of is totally different from regular quince. A normal quince is not something you would want to eat raw.
Cooked, however, a few slices of regular quince go well with vanilla icecream. The flavor is pungently deep, almost like cough syrup, and like a very tart intense heirloom apple, some people perceive a slight caramel aroma. Using a ratio of 40% quince to 60% apple also goes well in an apple pie, and then you don't have to use any added thickener in the filling. It will give the apple pie a more intense flavor.
It also of course makes a good preserve spread. Long ago the original marmalade was made out of quince before the sour orange was brought to Europe. I think some of the best jam in the world is boysenberry-quince (and again because of the quince you don't have to add pectin if you make it).