In The Guardian, David Hockney spoke about some of his favourite painters a few weeks ago, an extract from a book he has written with Martin Gayford.
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Hockney talks about Giotto, Masaccio, Van Eyck and Vermeer and, at the end, brings up Rembrandt :
In a way, Vermeer and Rembrandt are opposites. But Rembrandt is the greater artist, I think, because he’s got more ingredients than Vermeer. Rembrandt put more in the face than anyone else ever has, before or since, because he saw more. And that was not a matter of using a camera. That was to do with his heart. The Chinese say you need three things for paintings: the hand, the eye and the heart. I think that remark is very, very good. Two won’t do. A good eye and heart is not enough, neither is a good hand and eye. It applies to every drawing and painting Rembrandt ever made. His work is a great example of the hand, the eye – and the heart. There is incredible empathy in it.
Rembrandt's artistic output was many times greater than Vermeer of course, who is thought to have painted only about 34 pictures (source).