You do have a good point antfreire. No singer can be great at everything and none of these singers were. Nonetheless while I do try to be neutral until I hear the prerformance, I still do have favourites and prejudices. Mind you these change every so often so in a couple of months time I would probably give a different answer. The one constant is that I do not like the Callas sound, and am ambivalent, at best, about the Caruso sound. I am not questioning their greatness, as great singing is about much more than just voice.
One of the joys of this site is (was) the discovery of singers I had never heard or often heard of. With reduced activity now it is less frequent but still does occur.
Discussion of contemporary singers: Jonas Kaufmann, Juan Diego Flórez, Anna Netrebko, etc.