With Sutherland, it can matter at what age you hear her. Her voice did not always age well, and you can hear it on some recordings more than others. When she was young though, she was as good as anyone (though diction was often an issue even then) and sometimes better.
The voice and technique were stunning, that is true, and I do enjoy her
Art of the Prima Donna set, for instance, but she is a singer who never really "speaks" to me, and even that recital I can only take piecemeal. I've tried and tried, but I can think of very few of the operas she sang that I don't actually prefer sung by someone else. Even in
La Fille de Regiment which is brim full of breath taking vocal feats, the mushy diction drives me potty. Pavarotti, on the same recording, sings with a terrible French accent, but his diction is so good, you can hear just how bad hers is. I know it bothers most people a lot less than me, but it irritates me terribly and consequently I have very few of her recordings.
Incidentally, on the live 1959
Lucia di Lammermoor from Covent Garden which made her a star, her diction is pretty good. Tullio Serafin was in the pit, so maybe that had something to do with it. He actually thought she should go on to sing more dramatic fare, and said he thought she'd have made an excellent Lady Macbeth. The voice was huge. Maybe she would have.
