This sounds like the lens is very bad and unusable, but that's not the case. When used in low light at very wide apertures, this lens can produce some very interesting pictures with shallow depth of field, and I am very happy with it, and used it quite a bit on my Panasonic G1, but not much on the NEX.
Definitely not the lens for landscape.
Frozen lake, note the vignette - NEX-6 & JML 50mm f0.95 @ f5.6. Click for larger.
Boats, slightly cropped - NEX-6 & JML 50mm f0.95 @ f5.6. Click for larger.