Under Construction -- NEX-5N & Sun Xebec 135mm f3.5 in Exakar Mount.
Didn't have much time to shoot a lot of pictures today, but I managed to spend sometime with the NEX-5N. The most obvious and noticeable improvement is the speed of operation. Everything seems faster (except image write time to the SD card seems a bit longer, but it could be because the card is slow [class 4] and the 5N's files are larger, and I was shooting RAW+JPEG. There is a big improvement in image quality. I downloaded a trial version of the Capture One RAW converter and looked at the 5N RAW files and found that ISO 100 is very clean. But, starting with ISO 800, details starting to smear a bit but still excellent. Much better than what I could get from the original NEX-5.
I meant to do a side by side comparison with the NEX-5 and the NEX-5N, but I already found a buyer for my NEX-5, and sold the camera this morning, so I guess that would be out of the question. Does the image quality warrant an upgrade from NEX-5 (or NEX-3 or 3C)? It all depends on what you consider acceptable. Many people are happy with the NEX-5's images, but I was never quite that happy with it. The 5N has much cleaner files from low to high ISO settings. So, yes, to me, it's worth it. It cost me around $350 for the upgrade (difference between the NEX-5 I sold and what I paid for the 5N), but considering I have been using the camera nearly everyday for almost nine months, it is not so bad.