http://www.the-digital-picture.com/N...aspx?News=8670

This is a very interesting lens! It has the same aperture/focal length as my beloved Minolta 600mm f/6.3 but with AF and IS, I don't think the image quality will be near as good as my prime but it will give a much better keeper rate and to be able to get images near impossible without it. The main thing for me is the compression and amount of background blur will be essentially the same as my lens.

I probably won't be selling my lens unless the IQ really surprises me.

Cheers,
John.