[Brightcolours]

Been there, done that, there is a difference in IQ, period.

The difference beween theory and practice, on theory, is none.

There is no real difference in IQ, actually. If I take 2 equivalent images, it is very difficult to say which is which. At the same time, I can't really tell the difference when I take an image at ISO 100, 200 or 400 with my 6D.

In theory and practice, there is no significant difference in IQ. Unless one is allergic to shadows or into pixel peeping instead of making photos...