I have been using a NEX-5 with hoodman viewing and various Leica lenses including 35mm Summicron, 28mm Elamrit, 50 mm Elmar and 400 mm Telyt. All have to be manually focussed. The longer the lens the easier it is to get dead on focussing. The hoodman keeps out the light and the screen detail is amazing, much better than viewing through the optical viewer on my Leica M6. Focussing using the tools that Sony has added - zoom in to 7x and 14 x level, plus the peaking level indicator allows for very accurate focus. You can for instance focus on an eye, or on the edge of a spectacle frame -which is within 1/2 an inch. DOF is very narrow with a 70mm lens, something you don't realize when using autofocus on most cameras.
To compensate for the characteristics of these lenses (the 28mm is too sharp and contrasty for many subjects, and the 50 year old Elmar is too soft for anything but portraits, but it is sharp as a tack - just low contrast) I set the image mode choices (vivid, landscape, portrait, standard etc.) one for each lens. Each choice can be customized for contrast saturation and sharpness. SO its easy to preset "vivid" with +1 contrast and +1 sharpness for the old ELmar lens to brighten the image up, ot to set Standard with -1 contrast and -1 sharpness for the Elmarit 28mm to soften its images.
With the latest firmware the adjustments are quick and easy. Everything can be adjusted with the eye up to the viewing hood, with exposure and focussing under the left finger and right thumb.
The experience with this combo is close to that of my M6.
When the NEX-7 is in production the NEX-5 will go to my wife.
By the way, I have 14 other Digital cameras including D70, LC10, Digilux 1, Panasonics of all kinds, Fuji S100fs, Canon digicams, Nikon digicams - this NEX-5 is a much better camera with the Leica lenses. I have spent a weekend with an M8, and it wasn't so exciting as I expected - I think the controls on the NEX-5 are better, the focussing certainly is.
Addendum 9/11
Regarding the difficulty of getting a sharp images in natural light.
What I notice, now that I have this ability to see accurately the DOF, is that after I manually focus on an eye so that the eyelashes are tack sharp, if I move my body position ever so slightly, the sharpness is lost. In fact I found it to be quicker to move my body forwards and backwards watching for the sharpest focus on the zoomed in screen, then quickly pressing the shutter, than it was to try and adjust the lens itself for accurate focus.
If you really want images to be tack sharp the camera has to be on a tripod, the exposure time 1/1000 sec, and the subject still as a stone!
