The attached photo shows the NEX-5 with the Voigtlander Ultron 28mm f/2 lens. It is mounted with a Rayqual Leica M to NEX adapter which cost $220.00 US. Voigtlander also makes a good quality adapter for $179.00 US. There have been some problems reported with the cheaper adapters that don't secure the lens tightly which can make focusing difficult.
This lens is high quality and in line with the feel of the NEX. The Voitlander is all metal so it is heavier than the Sony 18-55mm while being physically smaller.
Manual focusing has some benefits. It makes you think and plan a little more. Like with film when every frame is precious. The NEX will still auto adjust ISO and shutter speed. I have mine set to auto ISO and aperture priority. In addition, the 7X and 14X focus assist is very helpful. Quick shots are out of the question unless you pre-focus.
I found one problem with this setup. After taking a photo, the image review screen is accurate, but when I press the enlarge button, the image completely breaks down and is unviewable. If I turn the camera off then back on again, I can enlarge the image but the colors have a greenish tint. I've contacted Sony support to see if they have any suggestions. Haven't heard back from them yet.
All and all it's been a positive experience. I'll post an image or two as soon as I get a chance.