I have been following this thread and for me, professional grade represents the ability to deliver reliable results in demanding situations.
I have also found this article below which I feel should be read for this thread discussion.
http://www.luminous-landscape.com/reviews/cameras/E-3-Second.shtml
Thanks for posting. Seems like there are issues with AF, C-AF, ISO / banding issues. I am surprised that there is problem with AF working on that guys face. Should not be a problem. I rarely have issues with the AF, and I find that nearly 99% of my shots are in focus with rarely a AF problem. As for C-AF, I thought it worked fine, but I will find a chance to test it again to see that. ISO problem....I sorta agree. I think at high ISO, the image quality ain't that great, even when shooting in RAW. Perhaps I still have to learn silky pix. Banding....dun really see what he means. Any comments from anyone else?